MDG-F Filter drop down values based on some rules

Hello

MDG-F Screens (Data Model 0G) are based on feeder class 'CL_USMD_ENTITY_VALUE2_PROXY'. May I know what object to change to limit the drop down values for a field?

Also if I have implemented an ABAP based search help (se11 search help) and want to pass some parameters to Search help function module exit to limit its output list, how can I do it from MDG?

Many Thanks in advance

regards

Pranav