Relationship Categories in Mass Change

Hi Experts ,

I have a requirement where user should be able to Mass Change Relationship categories.

If I go to "Mass Change" it shows me all BP Header fields.

I tried to uncheck "No Mass Change " for BP_REL entity in "Define Field Properties for UI" under UI Modelling but no luck

One thing I noticed is when I click on Mass Change in Nwbc it directly takes me to Define Selection screen but I clearly remember  first step for Mass change is "Determine Entity" then when we click next it take  to "define selection".

Please let me know how can make BP_REL part of Mass Change.Also how I will get first screen i.e. "Determine Entity".

Thankyou.

Regards,

Neethu Joy