There are multiple opportunities to get this achievement but the earliest comes during
Act 2 Part 1. After breaking into the building and having your accomplice enter the room and open the door for you, you go through a door where 3 enemies await you.
After the cutscene, charge your time blast (hold RB) and hit one of them to take all 3 of them out, gaining the achievement. There are more opportunities for this later in the game but this is one of the easiest ways to get it.