For example, I have a basic shape with a fill and stroke (or other kind of appearance effects applied to get this result):
From this, I want two separate shapes, each a simple filled shape with no stroke. One shape is the extracted fill part, and the other is a fill of the outline shape essentially:
Once I have these shapes I would like to further modify the center shape by subtracting other shapes from it, while retaining the original background shape. For example to end up with these two shapes:
The key constraint here is that I do not want to re-create the base shape in several different places to generate these two shapes. The base shape may change frequently, and it would take too much time to replace it in multiple places each time.
I can almost accomplish this by using two fills, one with offset path, but I don't know how to apply effects like pathfinder to one of the fills to merge it with other shapes.