Hi Sandeep,
It should trigger this badi or you can also try with exit CNEX0005/CNEX0008 which will trigger with CN02 t-code.
Or you can follow the path spro->SAP Reference IMG->Project System->Structures->Templates->Standard Network->Enhancements for standard networks->Create Customer-Specific Fields in a Standard Network.
Check the documentation for more details.
Regards,
K.Srikanth Reddy.