Accessing to playercontroller.

If I follow this instructions any actor can access to playercontroller, and playercontroller affects the whole world. How to do so that only controlled pawn can access to its playercontroller? I have specific functions in playercontroller which must affect the only one pawn.

See here:

The playercontroller is essentially a projection of the players will onto the pawn.

If you only have one player you can also handle stuff in the playercharacter or corresponding pawn blueprint.