Monks get the Flurry of Blows ability as part of the Ki feature at 2nd level (PHB, p. 78):
Immediately after you take the Attack action on your turn, you can spend 1 ki point to make two unarmed strikes as a bonus action.
It seems that this means the bonus action has to happen immediately, implying that the monk can't move between the attack and the bonus action. That's fine, but what if the monk is surrounded by enemies? Can the Flurry of Blows be targeted at a different target than the original attack action? How about each individual hit of the FoB, can they each target a different enemy?
My DM seems to think that because it is considered to be only one bonus action that it can only affect one target. I know that in the end his ruling is law, but wondered if anyone had any insight into how this is actually supposed to be ruled.