Because I don't have many "Other" files (in this particular MC Library), I have the views a little "buried down", but you can put them wherever in your hierarchy you want. If, instead, you want to make a specific-view that shows just your Comedy files, for example, you could make a new view right under Video in the tree, and set it up like this:
Click to embiggen.*I should note: The fact that you cannot modify the [Media Sub Type] value list yourself has been long discussed here, for years. The current system (where you can't manually change those value lists) is, apparently, non-negotiable for JRiver. They're willing to add new items to the list (and have)
if we all agree on them, but their goal is to keep that list reasonably small and "coarse".
If you want subcategorization, this is the recommended approach. It will give you the utmost flexibility, and also protect your metadata should JRiver decide to modify this scheme in the future.
A nice side-benefit to this approach, is that you can combine different Media Sub Types into "unified views". For example, I have this view in my Library:
Click to embiggen.In that view, it doesn't matter if [Media Sub Type] is set to TV Show, Other, or Movie. If it is a Video, and it has Documentary in the [Genre] tag, it shows up in that view. That's nice for Documentaries because sometimes they're episodes of Nova, sometimes they're "movies" (either "real" ones, or maybe one-off "specials" on BBC or whatever), and sometimes they're whatever. This views them all in one place, and allows MC's automatic metadata lookup system to even automatically "assist" me in tagging them this way (because TMDB includes "Documentary" = [Genre] for most appropriate "movie-length" documentaries).
Plus, then I can set up a Tag on Import rule for TV Shows like Nature, Nova, and whatever to automatically add [Genre] = Documentary for me at import, so those don't need to be manually tagged to show up there either.
And, as the pièce de résistance, you can see in that screenshot above, that I
also have a Documentaries view "underneath" my main TV Shows view. This is a duplicate of the main Documentaries view. You can just drag/drop the view itself in the tree and drop it on another node, and then choose "Copy" from the pop up choices to create a duplicate. Then, I just modify it to include a [Media Sub Type] = TV Shows filter.
Any, or all of these can then be imported into Theater View or Media Network, and tweaked to work best in those view modes.