Having Trouble using filter function in NESTED CDT

Hi Everyone,

I have requirement to retrieve resulting CDT list by filtering nested CDT list containing key-value Tier:1 in nested CDT.

This is CDT list

     local: list    {
                    	{
                    		ReportFacilityId:30803, 
                    		FacilityId:3551, 
                    		FormInstanceId:4271964, 
                    		FacilityName:"Test 1", 
                    		IsSectionLarger:false, 
                    		FacilityMode:
                    		{
                    			{
                    			A15LinkModeId:17394, 
                    			ModeId:4, 
                    			ToS: 1,
                    			Tier:1
                    			}, 
                    			{
                    			A15LinkModeId:17394, 
                    			ModeId:4, 
                    			ToS: 3,
                    			Tier:2
                    			}
                    		}
                    	},
                    	{
                    		ReportFacilityId:30804, 
                    		FacilityId:3552, 
                    		FormInstanceId:4271964, 
                    		FacilityName:"Test 1", 
                    		IsSectionLarger:false, 
                    		FacilityMode:
                    			{
                    			A15LinkModeId:17394, 
                    			ModeId:4, 
                    			ToS: 1,
                    			Tier:1
                    			},
                    			{
                    			A15LinkModeId:17394, 
                    			ModeId:4, 
                    			ToS: 1,
                    			Tier:2
                    			},
                    			
                    	},
                    
                    
                    }
                    
                    
                    
    /* what I want to retrieve is list with  Tier: 1 FacilityMode */
    filteredList: {
                    	{
                    		ReportFacilityId:30803, 
                    		FacilityId:3551, 
                    		FormInstanceId:4271964, 
                    		FacilityName:"Test 1", 
                    		IsSectionLarger:false, 
                    		FacilityMode:
                    		{
                    			{
                    			A15LinkModeId:17394, 
                    			ModeId:4, 
                    			ToS: 1,
                    			Tier:1
                    			}
                    		}
                    	},
                    	{
                    		ReportFacilityId:30804, 
                    		FacilityId:3552, 
                    		FormInstanceId:4271964, 
                    		FacilityName:"Test 1", 
                    		IsSectionLarger:false, 
                    		FacilityMode:
                    			{
                    			A15LinkModeId:17394, 
                    			ModeId:4, 
                    			ToS: 1,
                    			Tier:1
                    			}
                    	},
                    
                    
                    }