A laser that reflects in a moveable mirror

I would try something like this:

Basically, this runs a line trace on a timer that checks to see if the surface it hit was a physical surface that is set to reflect (for more on physical materials, check here: Tutorials about Physical Materials in Unreal Engine | Unreal Engine 5.1 Documentation). If it does, it runs a series of bounces that continues as long as the end point of the trace runs into another reflection material. You can have this spawn actors such as cable actors that can appear as your laser beam that bounce around away from the player to reflective surfaces.