The Guest House is another of the trickier maps in the pool for hard, with lots of enclosed spaces and checks in areas you probably wouldn't think about if coming straight from the base game.

This first location is directly behind the truck, as pictured.

This one is found by simply looking left from the previous.

Directly opposite from the previous, this check is at the far end of the map.

This check is visible from the second location, up on the raised area to the right of the main house itself.

Down the alleyway separating the main house and the previous location, and to the left, down where Snake is held in the main game, these two checks are right next to each other.

From the previous, return up the ramp and out the door, and directly across the alleyway there will be a ramp leading up to a door. Go through that door and into the building a little bit and your surround indicator should lead you to this check in the pantry, if it's there.