When selecting "Relate Document" within a document, only have to select the document you are relating it to

Currently when trying to relate a document, if you select "relate document" within a document, you still have to search for and select both sides of the relationship. If I am selecting "relate document" through one of the documents I am trying to relate, I should only have to select the one other document I am trying to relate to that document. Searching for and selecting the document I am already in is redundant. I want to be able to duplicate and relate documents quickly.