How can you reverse the direction of alt-period in Bash?
If you supply a negative argument to Alt-., it reverses direction. The easiest way to do that (with standard keybindings) is Alt-- (equivalent to an argument of -1).
So, after one or more Alt-. keypresses, pressing Alt-- will cause the next Alt-. to go in the reverse direction. (Just ignore the argument dialog which appears when you press Alt--.)