Using more than 1 Depthmask to slice objects individually

I've got 2 depthmasks (which are reversed to mask anything above them) to slice 2 objects set up with 2 slider bars to adjust height. I have 2 objects inside each other and I'm trying to get the depthmasks to slice each object individually but I've ran into a problem with the way I'm trying to do it.

I've split each depthmask and the object it effects on a different layer. I've used multiple cameras to render each layer separately so each depthmask doesn't effect other objects. I've ran into the problem of since I have multiple cameras to render each object and the objects are inside each other, one object is always behind another because one camera renders on top of the other.

I want to find a way to render the 2 or more objects without one blocking the other and their depthmasks not to effect each other either.

I might need to refine this question I'm not very good at explaining this problem.