Seperate Shadow Strengths from different objects?

Is there a way I can separate the shadow strengths of different objects?

Like, maybe having its own Sun and its own Shadows. Where Object 1 has really dark shadows and Object 2 has some really light shadows.

I've tried Layers but it doesn't work for some reason. When I make a new layer and put it on both my Object 2 and Sun 2, it doesn't appear at all. I also tried enabling the culling mask on my main camera for the new layer.

I tried Google and searching here on Answers but couldn't find any answers (or even similar questions).

Thanks :)

Is there any way to do this?