HITMAN 3

All of these require following The Tour mission story to an extent. To eliminate Vidal, you need to become Corvo Black and then follow the mission story until you can ask a question on the tour. Bring the tour to the grape crusher and wait for Diana to create a distraction to push Vidal in.
For Yates, trigger Corvo Black's conversation, get a mercenary disguise and grab the poison from Yates' bathroom. Poison the cup at the head of the table in the meeting room, then meet with Corvo Black to progress the tour. Finally, unlock the security doors in the barrel room and take the sommelier's disguise, grab the Grand Paladin and talk to the guard to attend the meeting and kill Yates.
Finally, Wait for both targets to meet in the barrel room and this time poison the ventilation system to kill both of them with gas.