Yes. If you select the document migration checkboxes in the apps section under "Select for Extraction", Migration Manager will search all drives for documents. If you elect to set "File Rules" for document migration, File Rules take precedence over these "canned" drive searches and can reduce the search map and therefore the time.
File Rules also gives you very helpful %tokens% that enable you to virtualize your File Rules for all users. See the section in the Migration Manager User's Guide that covers File Rules. That little guide will help you get the most from the tool and is worth spending 5-10 minutes reviewing. It's available on this help system at the top-most menu.