Well assuming real life pilots know where they are when they get briefed, they also have maps and logbooks, lists over airfields with frequencies and field info, etc.
I feel like using the F10 map (with no enemy showing of course) is like looking it up in the book. Your option would be to print a list of airfields in the region and observe the briefing for your location. That being said, I do believe the topmost option in the ATC radio submenu is always the closest airfield and thus your starting point.