The Dot Product of 2 directional vectors will be in range of -1 to 1. Anything that’s above 0 is in front of you, anything below 0 is behind (and every other value in between matters, too!)
I grab all the actors around the player using a Sphere Overlap (as in the original suggestion) and loop through the elements of the array, checking my angles - Dot player’s forward and the direction to each target. For dot values greater than .5 I mark the target, and add that actor to the array - these are the baddies in my targeting cone:
Even though the one on the right is within range of the sphere, it’s not a valid target as it’s not in range of the requested >.5 dot product value.
To visualise it better, here are the dot values for this setup:
