Specific suggestions appreciated! Here is admin doc related section and more info on scopes. Here is github issue.
@kiol (I'm the author of that picture but I'm NOT Nextcloud developer :3)
I shared that picture since we need a way to communicate groups to a Nextcloud through OAuth.
So I see our need is something totally unrelated with your issue,
and probably also unrelated to OAuth scopes (but I'm not sure about this last thing - since maybe scopes could also be used to communicate groups - as a particular way to see scopes..maybe).