It says under the description for Distant Strike:
At 11th level, you gain the ability to pass between the planes in a blink of an eye. When you use the Attack action, you can teleport up to 10 feet before each attack to an unoccupied space you can see.
If you attack at least two different creatures with the action, you can make one additional attack with it against a third creature.
Would the only way to attack two different creatures be Two-Weapon Fighting?