Windchill OdataConnector - How to add Local Service to the Connector thing?

I have created Thingworx Windchill Odataconnector thing from OdataConnector template. All basic settings like ValidateConnection, GetEndPointList works fine. 

I want to add a custom service (Local Service) to call my custom rest End point added to the WTPart domain getCustomPartList().

I can add a new service as Route but I want to modify the data after calling the custom end point.

I tried me.getCustomPartList() but not working as expected.