Controlling different menu points in an ES Group?

Hi Si Team

Trying to get my head around Groups once and for all.
Am going to keep this simple:

https://www.finalbug.net/groups-learn-post-production-socially-fcpx-and-more/34-fcpx-foundations-videos
https://www.finalbug.net/groups-learn-post-production-socially-fcpx-and-more/38-fcpx-browser-mastery

Where on earth am I controlling whether videos turn up in the videos tab or not//when logged in not logged in?

https://www.finalbug.net/groups-learn-post-production-socially-fcpx-and-more/34-fcpx-foundations-videos/videos
https://www.finalbug.net/groups-learn-post-production-socially-fcpx-and-more/38-fcpx-browser-mastery/videos

Where on earth am I controlling whether discussions turn up/can be replied to/when logged in not logged in?

The Groups in question are open but require moderation to join...

I am guessing this is some kind of App ACL setting or am I way off?

thanks

Paul