Validation of BP role with BP Group in BP Create screen

Hello

We have linked BP Group KUNA with customer A/c Group KUNA.

We have created Role 1 which is customer based and Role 2 which is non-customer based (contact person).

The issue is that user can still create BP with following details i.e.

BP Group = KUNA

BP Role = Role 2

We want to restrict users to select ONLy Role 1 if BP Group is KUNA.

Is there a way to restrict? Using standard SAP we cannot do this but in case someone has done any development, or knows the solution, it will be really helpful

Thanks

Rakesh