It'll default to the first view that you have setup in Media Network, if you want it to go to another, just re-order them.
There isn't supposed to be any "folder" screen, since the main folders are to be navigated using the drawer, not the main screen, just like eg. the GMail app, you don't get a screen with all mail folders, you get the content from a folder immediately, and switch folders using the drawer.
The key difference is that in GMail 90% of the average non-power-user's interest is concentrated in one folder (the inbox), so that makes perfect sense there. It's a tougher issue when the user's interest is divided across multiple categories, but I have a suggestion if you're game (see below).
I suppose I can make it remember the last folder you were on more persistently and return to that, but its not going to get a "folder" view like Gizmo has, since the navigation drawer replaces that.
(I know that there is a glitch somewhere how you can actually get to such a view, but thats just because MCWS treats it like any other view)
Maybe one elegant solution to this issue is to do what Eos does. Like JRemote, Eos doesn't have a top level folder view and only uses the drawer for top level navigation. The key difference is that Eos always opens with the drawer pulled out so the first thing you see is the top level menu options.
I personally enjoy and prefer the top-level folder view in Gizmo, but I understand why it's undesirable from a modern UI perspective. The joy of the Eos method is that, even after using it daily for six months or so, I
never actually even noticed that Eos doesn't have a top-level folder view because it always launches with the drawer out, and 90% off my top level menu usage is when first switching to the app. By contrast, I (and some other folks, obviously) find myself vexed when opening JRemote and trying to switch media types (I think because it's not visually obvious that the drawer is there right at first, etc.). A few other media apps do the same thing (start with the drawer out, etc.)
Folks will eventually get used to it either way, but retraining will (on the margins) make some people skip/ditch the app, and this may be a way to split the difference. I understand if you don't think that's good design, but I thought I'd mention it as I (after having thought about it) think it's a pretty clever feature.