Mission 1 - Communication Breakdown

Secret 1: At the beginning of the mission, you'll need to take out the two guards next to the ruined shed. After killing the second guard with your thermal, head into the shed. The secret will be next to the generator.

Secret 2: When going under the dock of the large building, you'll jump up onto a ledge and have to kill the enemy standing directly in front of you. The secret will be to the right of the enemy under a staircase.

Secret 3: After detonating the explosives, head into the building to the right of your escape path. The Secret is upstairs on your right next to some guards.

Secret 4: once you're on your own, you will soon head up to a church where you will cover the other soldiers. As soon as you enter the church turn right and head up the stairs. The secret will be on the railing overlooking the 1st floor.

Mission 2 - From Out Of Nowhere

Secret 1: Secret one can be found about 80 meters from the overwatch. Once you've killed the first enemies and crossed the bridge, turn right and go up onto the platform. The secret will be behind a large rock.

Secret 2: After providing support for the other soldiers, you will need to pass trought a cave to reach the resort. Once out of the cave you will come to a mansion with an outside pool. Go straight past the pool and enter the mansion. The secret is under/behind the staircase as soon as you enter the mansion.

Secret 3:After progressing further into the mission, before heading up to the observatory, there will be a figure 8 shaped pool with a house behind it. Walk into the house and the secret will be to the right on a table.

Secret 4: Once you've reached the observatory you will see starts leading up to the sniping spot, instead of going up the stairs head left and enter a small room. The secret will be ontop of a box.