How to restrict the display of Requisition header level DFF to only Internal Requisitions

Content

Is there a way to display Requisition Header level DFFs only in case of Internal Requisition i.e. the Source Type is Inventory and not where the Source Type is Supplier.

I tried using EI for the Rendered property of Header DFF in Page Composer, 

#{bindings.SourceTypeCode.attributeValue == 'INTERNAL'} but this returns null.

I understand that SourceTypeCode is a line level attribute while DFF is at header level. Is there a way to do a join? Or if there is any other way to achieve this? Any help is appreciated.

 

Version

20D