Desire to not fill an object in a fill zone

Put both patterns on the same layer, so the innermost shape will be removed from the outermost shape’s fill.
In order for that to work, however, the inner shape must be closed. If it’s not closed, then it has no “inside” to remove and will get filled.
A quick test: Edit → Select Open Shapes should not select the inner shape. If it does, then Edit → Close selected paths may be your friend.