ExpGLDept - Epicor 9

I am looking to add ExpGLDept to a Crystal Report. ExpGLDept is displayed ONLY IN THE PURCHASE ORDER TRACKER screen. This field does not display on the Purchase Order screen. Purchase Order Tracker is the only screen where I see this field. I cannot find how to get this relation on the Detail screen, because the field does not display on the screen.

The POInvenoryLines construct on this form finds it. Since I cannot access the POInventoryLines construct, I need to know how to get back to ExpGLDept some other way.

How do I get ExpGLDept from the PODetail Line?