[GM] How can I....?

OK, I have a split screen game functioning,( on one computer), the problem I have is how to only switch one view to the second stage while the other player remains behind to finish the level with their own screnn view still, ( well I was having an Idea of how, but please if you know still reply because usually I get it about half right and have to keep at it for a while to get it right, thanks in advance).
Both characters start together on same map same game.

I'm sorry, i haven't had enough time to look into this yet. Have you figured it out yet though? If not I'll look into in a bit. As I have said before, I'm not sure that this is possible at all...but I'll try a few things.

It's alright, I kinda put it on the back burner for a moment, moving ahead with other things at the moment. So take your time.

Is an objective of the game to finish before the other player (all the levels)? If not, then you could just make the game wait until both get to the end of the level to go to the next one.

If this isn't the case, then one way I would attempt to do it is by making all of your maps persistent, this way no matter where your players are, the maps are running what they should be running. I haven't tried what you're doing, so I this is all just guessing.

This is all I can do to (try to) help right now.

Ok I messed with this as best I could, however I didn't have any luck. It seems that Gamemaker doesn't keep track of seperate rooms per port. I tried making it persistent as Purifier suggested as well, but with no luck. After doing abit more research on views, I'm leaning toward this as an impossibillty. The only thing I can think of to creatively counter-act this is to make all your multiplayer levels in one room. Just keeping them stacked high above/below one another to keep from seeing the other levels. But I would only suggest doing this if the levels were relatively short due to CPU and size consumption. An if I get something to work later on I'll get back to you on it.

I haven't had much luck either yet, has to be some way though, due to the fact that most mmo's aren't in just one room. I'm sure I'll find something, hopefully.