When Media entities are referenced by group content, via an entity reference field or wysiwyg, they should be added as group media.
The idea here is that the media ownership is tied to the group that the content is created in, so other group users can view and reuse them, without sharing between other groups.
1. Set up a site with Group, Group Node and Group Media.
2. Create a piece of group node content, with a media entity reference field.
3. Look in the group's media listing, the media item is missing.
On save of group content, attach related media to the group.
Active
4.0
Code
Oops, this already exists and works fine.
The option is in the group content settings for the media types.
And if anyone needs media inside of paragraphs, use groupmedia_paragraphs.