How to add custom attribute in Bankdata details SAP MDG

[pratikw2111]

I am trying to add timestamp ZZTIMESTAMP field in BUT0BK table which will be displayed at UI level. Whenever user is creating/changing BP and he add/change Bank data then this custom attribute ZZTIMESTAMP will be updated by user.

This timestamp field will be available at Bankdata details at UI level whenever user is creating/changin BP in SAP MDG through CR.

I am unable to enhance standard structure for SMT mapping which is BUS_EI_BUPA_BANKDETAIL. 

There is similar post 

https://community.sap.com/t5/technology-q-a/error-in-smt-mapping-adding-field-in-bank-details-mdg-su...

But there is no concrete solution. Any solution on this where we can enhance Bankdetail Entity at UI level using custom attribute.

If respective staging and api structure can't be enhanced then if there is any solution where we can update the custom attribute using handler class. Can someone provide steps and sample code for the same will be really helpful.

We are using MDG co-deployment solution.

Thanks & Regards

Pratik Wankhade