You can't start more than one level at once, because loading a level closes the other. What you can do is placing the terrains of map entities or models of the different environments in a distance of 10000 of quants from each other, and place a camera within each of them with its own view within the frames of the screen.
yes. tats a possibility. in one of the splits, i wanted to have a combined one like the full building. this way means there gonna be duplicate map entities.
you could make your own 'level loading' function and define which models to load in a txt file, allowing for 4 arbitrary 'level's to load up (and still seperate them in space sufficiently as pappe said.
It can be done pretty easily with Win32 calls. I did this in C# a couple of weeks ago, and i got 2 independant levels loaded into a form. 4 would be no problem.
I know i used C#, but it can be done the same way in Lite-C/c++.
@Scorpion: Not really just showing here. Else video would have been the best option. But camera manipulation is also there (though its just a visualization).
@DJBMASTER: Yes, i also found in the manual, 2 instance or more of the engine can be loaded when using the engine SDK in C++. So loading them onto a form will do it. But right now I would want to stick to using only Lite-C.