Hi ,
I have an multilevel test class but problem is i dotn see 100% coverage for the tests
 Tests class is 

@isTest
public class testGetAllLevels { 

static testMethod void testGetLevel1()
{
    Case_Type_Data__c obj = new Case_Type_Data__c();
    obj.Level_1__c = 'Test Level 1';
    insert obj;
    List<String> s = PickListHandler.getLevel1();

}
    
static testMethod void testGetLevel2()
{
    Case_Type_Data__c obj = new Case_Type_Data__c();
    obj.Level_1__c = 'Test Level 1';
    obj.Level_2__c = 'Test Level 2';
    insert obj;
    List<String> s = PickListHandler.getLevel2('test');

}
    
static testMethod void testGetLevel3()
{
    Case_Type_Data__c obj = new Case_Type_Data__c();
    obj.Level_1__c = 'Test Level 1';
    obj.Level_2__c = 'Test Level 2';
    obj.Level_3__c = 'Test Level 2';
    insert obj;
    List<String> s = PickListHandler.getLevel3('test1','test2');

}
    
 
    
}

The apex class is below

public class PickListHandler {
    @AuraEnabled
    public static List<String> getLevel1(){
    List<String> tempLst1 = new List<String>();
        for(AggregateResult  ar : [select Level_1__c,COUNT(id) from Case_Type_Data__c  group by Level_1__c])
    {
        tempLst1.add(''+ar.get('Level_1__c'));
    }

    return tempLst1;
      
      
    } 
    
    @AuraEnabled
    public static List<String> getLevel2(string strName){
    List<String> tempLst2 = new List<String>();
       for(AggregateResult  ar : [select Level_2__c,COUNT(id) from Case_Type_Data__c where Level_1__c=:strName  group by Level_2__c])
    {
       tempLst2.add(''+ar.get('Level_2__c'));
    }

    return tempLst2;
      
    } 
    
    @AuraEnabled
    public static List<String> getLevel3(string strName1,string strName2){
     List<String> tempLst3 = new List<String>();
      for(AggregateResult  ar : [select Level_3__c,COUNT(id) from Case_Type_Data__c  where Level_1__c=:strName1 and Level_2__c=:strName2 group by Level_3__c])
    {
       tempLst3.add(''+ar.get('Level_3__c'));
    }

    return tempLst3;
      
      
    } 
   

}

here is coverage

Your help is highly appreciated
Regards,
Carolyn​​​​​​​