Hi,
if you look at the fsm in charge of sending the chat, you will see how it's use.
first, I get a list of players in the room, when the user has choose to which player to send something, you can then use PhotonViewRpcBroadcastFsmEventToPlayer.
you send a global playmaker event, and this action make sure thatt amongst all players in the room, only the targeted one will get that global event called.
Have you looked the demo fsm?
Bye,
Jean