[Request] Where is my created map in the Content Editor?

I just learned the hard way because I reverted to an older revision in Perforce and the starter map I had changed didn’t get checked in at all before so I’m back to the original map (which apparently did get checked in at some point? Probably when I set up the repository through Perforce for the first time).

I don’t really understand why there is a Maps folder but the maps in there don’t actually show? Seems pretty counter-intuitive. By that logic, all the other starter content shouldn’t show either. Can you explain this in more detail?