Hive Mind triggers, causing each opponent to copy Selective Memory.
Resolve an opponent's Selective Memory, causing you to search their library for all nonland cards and exile them due to Opposition Agent, with the ability to play them from exile.
Repeat step 3 for each remaining opponent.
Resolve your Selective Memory, exiling nothing from your library.
Results
Cast any number of spell(s) from opponents' libraries.
Exile all nonland cards from opponents' libraries.