How do I add the same contacts to multiple mailing lists in Contacts.app?

I use the "Send email to [name of group]" option in Mac Contacts. It's fast , efficient, and organized. I have run into a problem when I add a contact to Contacts group. Instead of adding a reference to a new list, the software actually removes the contact from any other group that it is in and adds it to the new group. In effect, it "moves" rather than "copies" or makes a reference. **I need to build multiple mailing lists (groups) and some people I'm mailing to need to be on different lists for different reasons.** **Is this possible?** Contacts is Version 2536, on Ventura 13.0