Since we can now display the saved search under Synchro field, it may be easier to find a document under Documents or Connections.
From there if the document exist under Plan Set, a Go To link should exist to allow user to move back and forth between the two location
The documents (drawings) in the plan set should not be copies of the documents in ProjectWise. Instead, they should either be mirrored or linked directly from the plan set to the documents in ProjectWise.