1. for this first version, the apex:dynamicComponent is not needed at all but it is my draft code and the next version should be much better
2. I read all the values of CObject1, CObject1 and CObject3 at the beginning (theoretical and not real world).

<apex:page standardController="Contact" extensions="DynamicHierarchyComponent">  
    <apex:pageblock >	
        <apex:dynamicComponent componentValue="{!Hierarchy}"/>				
    </apex:pageblock>	
</apex:page>

public class DynamicHierarchyComponent {
    public DynamicHierarchyComponent(ApexPages.StandardController con) { }
    
    public List<String> items {get;set;}
    
    static Map<String,Map<Id,List<sObject>>> allvalues;
    
    static  Map<Id,List<sObject>> parentmap(String object_name){
        List<sObject> c2 =  Database.query('select id,name,parent__c from ' + object_name + ' order by name');    
        Map<Id,List<sObject>> m2 = new  Map<Id,List<sObject>>();
        String parentid = '';
        for (sObject o2:c2) {
            parentid = null;
            if (object_name == 'CObject_2__c') {
                parentid = ((CObject_2__c) o2).parent__c;
            } 
            if (object_name == 'CObject_3__c') {
                parentid = ((CObject_3__c) o2).parent__c;
            } 
            if (parentid == null) continue;
            if (m2.containsKey(parentid)) {
                ((List<sObject>) m2.get(parentid)).add(o2);
            } else {
                m2.put(parentid, new List<sObject>{o2});
            }
        }
        return m2;
    }
    
    public  Component.Apex.PageBlockTable getHierarchy() {
        
        Map<Id,CObject_1__c> c1 = new  Map<Id,CObject_1__c>([select id,name from CObject_1__c order by name]);      
        allvalues = new  Map<String,Map<Id,List<sObject>>>(); 
        allvalues.put('CObject_2__c',parentmap('CObject_2__c'));
        allvalues.put('CObject_3__c',parentmap('CObject_3__c'));
        
        items = new List<String>();
        Component.Apex.PageBlockTable myTable = new  Component.Apex.PageBlockTable(var='item');
        myTable.expressions.value = '{!items}';
        
        Component.Apex.column clm = new Component.Apex.column(headerValue= 'Name'); 
        myTable.childComponents.add( clm );
        Component.Apex.OutputText outText = new Component.Apex.OutputText( );			
        outText.expressions.value = '{!item}';			
        clm.childComponents.add( outText );		
        
        for (Id id1 :c1.keyset()) {
            CObject_1__c o1 = (CObject_1__c) c1.get(id1);
            items.add(o1.name);
            getNodes('CObject_2__c',o1.id);
        }            
        return myTable;
    }
    public void getNodes(String object_name,String parentid) {        
        String name = '';
        String id = '';        
        Map<Id,List<sObject>> map1 = (Map<Id,List<sObject>>) allvalues.get(object_name);      
        if (object_name == 'CObject_2__c') {
            if (map1.containsKey(parentid)) {
                List<CObject_2__c> lcob = (List<CObject_2__c>) map1.get(parentid);
                for (CObject_2__c cob:lcob) {
                    name = cob.name;
                    items.add('*** ' + name);
                    getNodes('CObject_3__c',cob.id);
                }
            }     
        } else
            if (object_name == 'CObject_3__c') {
                if (map1.containsKey(parentid)) {
                    List<CObject_3__c> lcob = (List<CObject_3__c>) map1.get(parentid);
                    for (CObject_3__c cob:lcob) {
                        name = cob.name;
                        items.add('****** ' + name);
                    }
                }   
            }      
    }
}