APEX controller code:

//APEX
public with sharing class ListContent_Extension 
{
    public Content__c con;

    private Set<String> cID = new Set<string>();

    private User currentUser = new User();
    
    public List<Content__c> contents {get;set;}
    public List<String> services {get; set;}
    public List<String> contentType {get; set;}
    public List<String> fileType {get; set;}
    
    public String searchField {get; set;}
    public String sortField {get; set;}
    public String previousSortField {get; set;}
    public String Id {get; set;}
    public String errorMessage {get;set;}
    public Boolean errorFlag {get;set;}
    
    public ListContent_Extension(ApexPages.StandardController stdController)
    {
        this.con = (Content__c)stdController.getRecord();
        init();
    }
    
    public void init()
    {
        contents = new List<Content__c>();
        currentUser = [Select Account__c, Account_Name__c, Business_Unit__c, Id from User where Id = :UserInfo.getUserId()];
        String[] uBU = currentUser.Business_Unit__c.split(';'); //USER BUSINESS UNIT
        
        //RETRIEVE CONTENT ID'S AND CREATE DISTINCT SET REGARDLESS OF HOW MANY BUSINESS UNITS CONTENT BELONGS TO
        for(Content__c c :[SELECT ID, Business_Unit__c FROM Content__c WHERE University__c = :currentUser.Account__c ])
        {
            String[] cBU = c.Business_Unit__c.split(';'); //CONTENT BUSINESS UNIT
                  
            for (string unit : uBU)
            {
                for (string item : cBU)
                {
                    if (item == unit)
                    {
                        cID.add(c.Id); //cID IS A SET OF CONTENT RECORD ID'S. SETS CONTAIN ONLY UNIQUE RECORDS
                    }
                }
            }         
        }      

        //RETRIEVE RECORDS FOR DISPLAY
        for(Content__c cRecs :[SELECT Id, Services__c, Content_Type__c, Comments__c, Download_Date__c, 
                               CreatedDate, Name, University__c, S3_URL__c, File_Type__c, Author_Search__c 
                           FROM Content__c WHERE Id IN :cID ORDER BY CreatedDate DESC])
        {
            contents.add(cRecs);
        }      
    }   
    
    //USED BY SEARCH FORM
    public List<SelectOption> getServicesItems() {
        
        List<SelectOption> options = new List<SelectOption>();
      
        for(String s:Utilities.getServices()){
            options.add(new SelectOption(s,s));
        }
        return options;
    }
    
    public List<SelectOption> getContentTypeItems() {
        
        List<SelectOption> options = new List<SelectOption>();
        
        for(String s:Utilities.getContentType()){
            options.add(new SelectOption(s,s));
        }
        return options;
    }
    
    public List<SelectOption> getFileTypeItems()
    {
        List<SelectOption> options = new List<SelectOption>();
        
        for(String s : Utilities.getFileTypes())
        {
            options.add(new SelectOption(s,s));
        }
        return options;
    }

    //HEADER SORT CODE
    //FROM http://wiki.developerforce.com/index.php/Sorting_Tables          
    public void doSort()
    {
        String order = 'asc';
        
        //CHECKS IF SAME HEADER CLICKED TWO TIMES IN A ROW IF SO REVERSES THE ORDER
        if(previousSortField == sortField)
        {
            order = 'desc';
            previousSortField = null;
        }
        else
        {
            previousSortField = sortField;
        }
       
        //THIS CALL DOES ALL THE WORK
        if(contents.size()>1)
        {
            superSort.sortList(contents,sortField,order);
        }
    }
    
    //EDIT SINGLE CONTENT ITEM
    public PageReference editPage() 
    {
        string strURL = '/apex/ListContentEdit?file=' + Id;
       
        PageReference editPage = new PageReference(strURL); 
        editPage.setRedirect(true);

        return editPage;
    }    
    
    //DOWNLOAD ITEM
    public void download()
    {
        if (currentUser.Account_Name__c <> 'Ruffalo Cody')
        {
            Content__c file = [SELECT Downloaded_By__c, Download_Date__c FROM Content__c WHERE Id = :Id];
            file.Downloaded_By__c = currentUser.Id;
            file.Download_Date__c = date.Today();
            update file;
            executeSearch();
        }
    }   
    
    public PageReference executeSearch()
    {    
        errorFlag = false;
        String strQuery = 'ID, Services__c, Content_Type__c, Comments__c, Download_Date__c, ';
        strQuery += 'CreatedDate, Name, University__c, S3_URL__c, File_Type__c, Author_Search__c';
        
        //BASIC WHERE CLAUSE MUST CONTAIN BUSINESS UNIT AND UNIVERSITY CONSTRAINTS
        String strWhere = ' WHERE University__c = \'' + currentUser.Account__c + '\' AND Id IN :cID';
        strWhere += buildWhereClause();
        
        String strSearch = 'FIND { ' + searchField + '* } IN ALL FIELDS RETURNING Content__c';
                 
        system.debug('Start Date: ' + con.Filter_Date_Start__c);
        system.debug('End Date: ' + con.Filter_Date_End__c);       
                 
        //VALIDATE DATE RANGE
        if (con.Filter_Date_Start__c <> NULL && con.Filter_Date_End__c <> NULL)
        {
            if (con.Filter_Date_Start__c > con.Filter_Date_End__c)
            {
                errorMessage = 'Created Date Range End must be equal to or after Created Date Range Start';
                errorFlag = true;
            } 
        }
            
        if(!errorFlag)
        {
            if (searchField != null && searchField.length() > 0) //SEARCH AND FILTER
            {
                if (searchField.Length() == 1) // NO SINGLE CHAR SEARCHES
                {
                    errorMessage = 'Search Term must be longer than 1 character';
                    errorFlag = true;
                }
                else //SEARCH
                {                
                    List<List<SObject>> searchList = search.query(strSearch + '(' + strQuery + strWhere + ' ORDER BY CreatedDate Desc LIMIT 200)');                
                    contents = (List<Content__c>)searchList.get(0);
                }
            }
            else //NO SEARCH TERM - JUST FILTER
            {
                String sqlQuery = 'SELECT ' + strQuery + ' FROM Content__c' + strWhere + ' ORDER BY CreatedDate Desc LIMIT 200';
                contents = Database.query(sqlQuery); 
            }
        }
            
        if (!errorFlag)
        {
            if(contents.size() <= 0)
            {
                errorMessage = 'No Records Found - Try Again';
                errorFlag = true;
            }
        }  
       
        PageReference searchPage = new PageReference('apex/ListContent/'); 
        searchPage.setRedirect(false);

        return searchPage; 
    }
    
    public String buildWhereClause()
    {
        String whereClause = '';
        
        //SERVICES FILTER (INCLUDES)
        if (services.size() > 0 && services[0] <> '')
        {
            whereClause += ' AND ';
            
            if (services.size() > 1)
            {
                whereClause += 'Services__c INCLUDES (\'';
                
                for (string service : services)
                {
                    whereClause += service + '\',\'';
                }
                whereClause = whereClause.substring(0,whereClause.length() - 3) + '\')';
            }  
            else //SINGLE VALUE
            {
                whereClause += 'Services__c INCLUDES (\'' + services[0] + '\')';
            }
        }
        
        //CONTENT TYPE FILTER (INCLUDES)
        if (contentType.size() > 0 && contentType[0] <> '')
        {
            whereClause += ' AND ';
            
            if (contentType.size() > 1)
            {
                whereClause += 'Content_Type__c INCLUDES (\'';
                
                for (string content : contentType)
                {
                    whereClause += content + '\',\'';
                }
                
                whereClause = whereClause.substring(0, whereClause.length() - 3) + '\')';
            }  
            else //SINGLE VALUE
            {
                whereClause += 'Content_Type__c INCLUDES (\'' + contentType[0] + '\')';
            }
        }
        
        //FILE TYPE FILTER
        if (fileType.size() > 0 && fileType[0] <> '')
        {
            whereClause += ' AND ';
            //whereClause = whereClause !='' ? whereClause + ' AND ' : '';
            
            if (fileType.size() > 1)
            {
                whereClause += '(';
                
                for (string file : fileType)
                {
                    whereClause += 'File_Type__c = \'' + file + '\' OR ';
                }
                
                whereClause = whereClause.substring(0, whereClause.length() - 4) + ')';
            }  
            else //SINGLE VALUE
            {
                whereClause += 'File_Type__c = \'' + fileType[0] + '\'';
            }
        }
        
        //DATE FILTERS
        //CREATED DATE > FILTER DATE START
        if (con.Filter_Date_Start__c <> NULL)
        {
            string strStart = string.valueOf(con.Filter_Date_Start__c);
            datetime startDt = datetime.valueOf(strStart + ' 00:00:00');
            
            string dtStart = startDt.format('yyyy-MM-dd') + 'T' + startDt.format('HH:mm:ss.SSS') + 'Z';
            whereClause += ' AND (CreatedDate > ' + dtStart + ')'; //CreatedDate greater than Midnight of selected date
        }
        
        //CREATED DATE < FILTER DATE END
        if (con.Filter_Date_End__c <> NULL)
        {
            string strEnd = string.valueOf(con.Filter_Date_End__c);
            datetime endDt = datetime.valueOf(strEnd + ' 00:00:00').addDays(1);
            
            string dtEnd = endDt.format('yyyy-MM-dd') + 'T' + endDt.format('HH:mm:ss.SSS') + 'Z';
            whereClause += ' AND (CreatedDate < ' + dtEnd + ')'; //CreatedDate less than Midnight of day following selected date
        }
        //whereClause = whereClause !='' ? whereClause + ' AND Content_Type__c like \'%' + contentType + '%\'': ' Content_Type__c like \'' + contentType + '%\'';
        //whereClause= whereClause!=''?whereClause+' and (Status__c!=\'Inactive\' or Status__c !=\'Terminated\')': ' (Status__c!=\'Inactive\' or Status__c !=\'Terminated\')';
        
        //******
        system.debug('WhereClause:' + whereClause);
        //******
        
        return  whereClause;
    }
    
    //CLEAR SEARCH AND RETURN TO FULL RESULTS
    public void clear()
    {
        services.clear();
        contentType.clear();
        fileType.clear();
        searchField = '';
        con.Filter_Date_Start__c = NULL;
        con.Filter_Date_End__c = NULL;
        executeSearch();
    }
}

 Test code eliminated for brevity.