Hey hey,
So I want to create a mechanic where the player presses a button to activate “scent mode” which will create a particle effect that will move from the player to the target actors/locations nearby.
Was simply wondering what would be the best way to go about doing the path. If I should use splines? Or maybe an AI that simply moves to the detected location?
You could use particles with an attraction location
You can have the attractor point at the key location, or move it progressively towards the location 
That second part would require something like a spline, maybe, or putting the emitter system in a blueprint that can home in on the focus point.
Sorry for the late reply, been rather busy with work. Thank you for the tip!
For the path, guess I could do it similar to a basic AI that “Goes to” location. Thanks once again.