2-D 3-layer bar graph

I need to create a 2-dimensional bar graph with three layers:

x-axis: months

Rear layer: target (this will be the widest bar: overlap 100, gap 50, currently on primary axis)

Middle layer: forecast (medium width: overlap 100, gap 220, currently first in order on secondary axis)

Front layer: actuals (narrowest: overlap 100, also secondary axis, gap currently 220, but would like this to be the thinnest bar)

I want to stack these one on top of the other with different widths so all are visible, but I when I adjust gap width, the middle and front layers change simultaneously (because they are on the same axis). That is, I can't set separate gaps to make sure they are both visible if they happen to have the same values. Example attached.

Thanks for your help in advance.