Looks like that was based off of one of my old examples.
Here's an updated example with additional PIP splitscreen. Mouse over each view to enable default arrow key controls for that view.
dropbox.com/s/435vzetis23i96r/4psplitscreenexample.c3p
I modified it a bit using a hud layer, containers for each camera/canvas pair, and using a for each 'view' to loop through them.
There's some issues going on when the main view leaves the original viewport, but I don't have the time to troubleshoot that right now. Edit: View objects dissapearing in a few other situations when they get close to each other as well.