Inclusion of custom fields to OWL Search

Hi

We have a business requirement to include custom fields (from Custom BO) as search parameters into the search screen (OWL) of a Standard BO (Business Partner);

The Custom BO fields are available for display, maintenance in the Standard BO via an embedded component in one of the facets of the Standard BO TI screen;

To our knowledge, it is only possible to include custom fields of the Standard BO only but not custom fields of the Custom BO.

Example: See attached pictures

We would like to search by Rel.Attribute value in the standard

Contacts Search OWL.

Looking for ways to enhance the Search OWL to include fields from the Custom BO as search parameters.

Any tips / advise would be appreciated here.

Thanks

Prasad