Resricting Drop down for displaying value dynamically

Dear,

Need to restrict  drop down values dynamically based on the value of other field.First I thought I will create a Search help exit and attach that search help exit at Data model level of perticular field. As the value will be populated dynamically based on other field value so this  purpose failed. Second Implemented enhancement spot USMD_UI_EVENT2 on that we can restrict drop down values dynamically by using method GET_ATTR_VALUES_SET. but this BADI is not triggering on below MM application.

I'm using MM data model.

Application : MDS_BS_MAT_OVP

UI configuration : BS_MAT_OVP_LAYOUT_03

If any one have worked other than than this method. Please let me know.

Regards,

Riyajuddin