Highest Difficulty - Question

[xIRockyRock]

The missions in this game are fairly long if you go fully stealth and tactical. On the highest difficulty it says „Complete [level] in one playthrough“ trophy wise.

 

So can I close the game and resume later on for completing every objective in one playthrough or is it meant to play every objective in one sitting (without closing the game)?

[Grand_JeepMazz]

Its like the first one you just have to complete 1 contract on the highest difficulty and finish the mission to have the trophy