using the nav option will launch the game on the map with no indication that is is doing the nav mess, if you look at the console at that moment tho you will find out that it is building a nav file (tf2 is usually laggy during that time). it will eventually close the game when the nav file is done. All this does is really just nav_generate, which is usually mostly fine if your geometry is simple enough.
you'll also need the "pack" option to include the nav file in your map. The nav should work without packing locally tho. Also, the nav option doesn't finish until a .nav file exists where it should be, check if it's actually in your maps folder.