I gave you an answer. It's still custom fields. Make one called Series Type for instance, or Video Type, if you want different categories for more video content. You can make a view based on this Video Type field, and then you have categories for Comedy shows, Action shows etc. You might want to set the Media Sub type to Series, or just use one Custom field for different series categories, home movies, music videos etc, movies, and bind it all to corresponding Theater View views.
For series you'd then have something like:
Video - Series (Media Subtype) - Show Type (Video Type) - Series Name - Seasons
I'm just using Video Type my self, and I have this values )among others): Series, Movies (HD & DVD), Movies (Divx), Conserts, Music Videos. This is Views under the Video root item, and have the Series name as categories under Series, and I have Seasons under there. Gives me quick access to what ever I want to watch.
I can't think of a cleaner way to browse TV Shows and getting a handful of results. You could also accomplish similar results with Keywords or genre, but I don't like that approach. It's better suited for music and images imo.
The only things you'll see at the bottom level in TV is the media it self, I believe. Don't really know why you want a sort of directory structure at the last level. Can't see any benefits. If this is a way that you want to play all episodes of a TV Show, then you allways have the Play all option.