I made it into a square, otherwise you’ll be fighting the engine all the way.
To make the green line move, you need to pan it in the Y direction
Try it on a plane first, to make sure it’s working
But when I put it on my arrow, I get
So I rotated the UVs in the material beforehand
Then I get
So it really depends which way around you have the texture, which way you pan it, and how the UVs are arranged on your mesh.
I’d advise not using world position, because you’ll have to keep changing the material every time you move your arrows. Here’s my material for that
Looks ok
Until I change the position of the mesh ( which you probably will do 
)
