Multiple cameras, each of one renders another set of GameObjects

Howdy!

There are two cameras I want to use. One renders all the game objects at the borders of a scene (sort of a GUI, though cannot use the Unity's GUI), the second camera should render the actual level contents "in the middle" of the scene, i.e. in a viewport that is smaller to the screen size.

I understand, that the camera has a viewport that can be lesser to the screen size.

However, at this moment, I would probably wish to tell Unity, that camera A should render the set of game objects A, and camera B should render the set of game objects B.

Possible?
Thank you

P.S. 've been searching already, yet no answer

 

..might probably put the "gui" and the "level" objects to coordinates, where the views (frustums) of camera A and B do not intersect, well...

 

Set the differents kind of objects (border and middle) on two different layers, and set the culling mask of each camera in order to see only one type of layer.

 

Thank you, now I know that there exist rendering layers. Will make it