Two or more scenes showing at once

[Steve 6 4 64]

I bet the answer to this is stupidly simple, but it seems to allude me. How do I get two or more scenes to show at the same time? I would like my video camera to be on top (small and upper left) and my screen to be underneath the video and full screen.

 

[koala]

Menu View->Multiview.
The Multiview is somewhat configurable in Settings->General->Multiview

 

[Suslik V]

There is Scene source, that can be added to other scene (to get scene in scene).

Any source can be resized (right-click menu ->Transform or by mouse move in preview - the red circles at corners of the selection rectangle of the source can be dragged).