STAR WARS Jedi: Fallen Order Deluxe Edition

For this you need the Force Power to throw your lightsaber.

Sounds easy enough: find a group of enemies and throw the lightsaber at them. Well, I tried a few times and had trouble aligning three enemies. I then used force push on a group of four troopers, walked around a corner and let them come to me. I slowed down the first around the corner which got them closer together.

I found this easiest on Kashyyk. It does require the Howling Pull Force ability and the Lightsaber Throw ability of course .
When you approach the Imperial Refinery, there will be a bunch of Stormtroopers guarding a blast door (including a Stormtrooper commander on a ledge). Force push the commander off the ledge so that he joins his comrades down below, then use Howling Pull which will pull all the Stormtroopers close to you. Throw your lightsaber at the group you have created and the achievement will pop if you hit three of them.

Also found a good easy spot during post game/ late game in Bogano there are a good amount of storm troopers after a specific mission and on the upper level parts to the right the Bogdo sinkholes area, it's super helpful to use the howling pull (LT+RT) to bring enemies close and then just throw the lightsaber, I also didn't lock to one I found it easier just to free aim it