How to Collect Reference Documents when Creating New ECR from a Document

Hi,

I have a question about Collect Object function. I am setting as a reference B document to A document from "References Documents" area at "Related Object" tab. Then, when I checked the B document's "Releated Object" tab, I can see the A document as referenced at "Referenced By Documents" area.

My question is; when I try to create new change request from the B document I cannot list the A document at "Affected Objects" ECR creating page. How can I create cross reference A document to B document for adding ECR affected object list.