Check while replacing approver in SC creation

Hello expert,

Whenever user replaces default approver using replace button in shopping cart creation, is there any badi exit through which i can validate the new user. I have already implemented BADI "BBP_CHNG_AGNT_GET".

This badi gets triggered when user clicks on find button. Sometimes user directly hit the replace button instead of find and then replace.

Thanks in advance.

Regards,

SVS