Business Partner - How can I add additional Search Criteria?

Hi All,

I am trying to add additional search criteria to the Business Partner search screen, but seem to be running into a few issues. On the screen below I would like to add the ability to search on Tax Category and Tax Number.

In MDG >>General Settings >> UI Modeling >> Define Field Properties for UI I de-checked the 'No Selection' and 'No Results List' checkbox for the BP_TAXNUM entity (as seen below).

This allowed me to add the Tax Number Category to the search criteria, however there was no Tax Number available (as seen below). Is there a reason why Tax Number is not available?

Also, when I tried to run a search using the Tax Number Category as a criteria, the following error was displayed.

Is the error referring to the query linked to the feeder class (see image below)? If so, how can I update the query to support additional search criteria?

If there is an easier way to add search criteria please let me know. I would really appreciate any help on this.

Thank you,

Peter