I tried to do some research on this topic on my own and the closest thing I found was from three years ago ( https://wpforo.com/community/how-to-and-troubleshooting-2/possible-to-duplicate-categories-and-related-forums/) but ultimately I need to be able have certain aspects shared between categories. For example, we have a section of the site that it is dedicated to Language & Culture. China and Taiwan both have Mandarin as the primary language, therefore Mandarin would be listed under both. If possible, I would like the content to be shared (only be one sub-forum). I have almost all of the paid addons but it does not appear to be a feature in any of them. Is this functionality possible?
I've just asked our developers about it and currently, I'm waiting for the response from them. I'll update the topic asap.
@alvina Were you able to find anything out about this functionality?