Do you mean so that only the last area render you did is the only one visible?

If so, I don't think there's a specific feature for it but I suppose you could always store the camera position, rotate to render under the floor so that you get a black render, then use the stored camera position to get your original view back and render a different area.

That said, I don't really understand why you want to do what you're asking so I'm probably misunderstanding what you're getting at.