How to add custom Attachment category in Supplier Negotiation header

Summary:

For Supplier negotiation header, customer wants to add select business specific categories while attaching the document before publishing the negotiation. Is there any way we can have customer category which can be created at the supplier negotiation header attachment?

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):