Field in sub shape link to custom props in main?

[Jason]

I have a shape with several custom properties. The shape is made up of two
rectangles. I would like to have customproperty1's value show up in the top
rectangles text and customproperty2's value to show up in the bottom
rectangles text. However, if I select one of the sub shapes and Insert ->
Field, they do not appear to share the custom properties of the main shape as
there is nothing displayed in the Fields box. Is there a way to do what I
have explained?

Thanks,
Jason