Window attributes question - 2D sash fill

[Andy Broomell]

How do I get a window to show up like this using only PIO parameters?

In the above I just drew two rectangles over the small sash rectangles.

 

Here's what I currently have from the window tool:

 

via these settings:

 

Which gets me the jamb with the section fill as desired.

 

But if I also assign "Sash" to the Section class, then I get this (where it fills the bottom sash in addition to the two side sashes):

 

What am I missing?

Thanks!