Obviously, it's pretty easy to pull the Owner of searches and reports, and those are usually the most important ones (although as the owner they'll retain access, even when they change roles, unless you've really curtailed their permissions). If you really need to get all the reports/searches they can access, best way is to have them go to Reports > Saved Reports > All Saved Reports and Reports > Saved Searches > All Saved Searches and then just export those lists. You could add the role to yourself and do the same thing, but that might miss ones that are assigned via user, department, etc. versus by role. Nine times out of ten they don't need most of the searches/reports they have access to, so asking them which ones they routinely use and then just being open to giving them 1 or 2 more down the line usually works too.