It’s rather straightforward to share to your page, or a page you own from YouTube. Not sure how to share to a group or someone else’s page without simply sharing an existing post. Even then, it seems to limit where it can be shared vs. creating a new post on the MT page. Trying to avoiding having to create a multitude of new posts as that is inefficient use of time. I’m sure there is a way, I’m just too much of a FB noob to know how.