I’m not sure if I understood this right, so in any case i’m sorry for not being very useful but you can illustrate or explain this better later. Do you want to shoot a thing left/right from the tip of the arrow??
Your arrow is rotated towards it’s target? Then you can grab the arrow’s rotation and get the RIGHT vector of it, and then idk, give it some multiplication and add it to the location just like you were doing there.
tldr instead of using the forward vector like in that image, use the right vector of the rotation of the arrow.
Sorry if i didn’t get this right
Edit: if you wanna go right, do that thing. If you wanna go left multiply the right vector by -1.