SAP MII SSC UI CUSTOMIZATION

In SAP MII SSC (Self Service Composition Dashboard),

There is some issue I am facing while doing some customization on the UI of SSC.

I added two UI5 drop down with Dynamic Data Source and my requirement is populating the second drop down

as per the selected value of the first drop-down.For that what I need to get the instance of first drop down

along with its selected value and then pass it as a parameter in query so that the second drop down can be populated.

The constraint lies in

1)Getting instance of the drop down to get the selected

I have tried adding some custom code to get the drop down instance but no help.Here is the part of the customized added

code

This is not giving any error but not working.

Please help.