How to Make an Object behind Another Seen?

So assuming I have two actors A and B, both are NOT transparent, and A is larger, and closer to the camera. Now, with both actors` visibility set to visible, and hidden false, is there anyway I can make B seen as if using an X-ray vision while keeping their relative distances to the camera the same(A is closer)?

Try something like this:

or

Thank you very much! These really solved the issue.