Post in Multiple Spaces

Suggestions on the best way to 'cross post.' For example, I have spaces for 'athletic equipment managers' and 'american football coaches.' A post about a new football helmet needs to be seen by both.

I notice that https://---.com/portal/post/thepostname works without the space identifier, so maybe that's a clue, but not sure how to identify multiple spaces without cluttering with duplicate posts. The 'space_id' in the database only accepts a single integer.

Even a 'link' type post that redirects to the other space would be fine, but not sure how to do that without a simple text body which doesn't look great.