What is it you are trying to achieve?
If you simply want to have a ‘scope’ or something for a night-vision camera on a sniper rifle, or whatever…: then you can simply use a Post Process material for the Capture 2D camera that does that effect - you don’t need a different material on the object to do that. You can even render objects out in to the custom depth buffer with different values for different objects, to get some really nice ‘heat’ effects on different object types, if you were to go this route.
If you only want a simple tiling material on different objects for the second camera view: you can do a world-aligned texture in the post process material, and use the custom depth buffer to blend different materials on to different objects in the post-process material.
Why do you need different materials on objects if they’re going to be rendered to a texture to look like a monitor though? Surely if a camera looks at an object and renders that on to a screen, it will look the same as if the player had looked at that object. Why do you need to use different materials? Surely what you’re trying to do can easily be achieved with a post process effect