Fake-light on a dynamic amount of spots on a material

Hey there!
I’m having a grid cell material which is applied to every cell on my grid, and I want to “light up” spots where the path on this grid traverses across.
The result should look similar to this photoshopped sketch:

I know I could pass coordinates down via a material instance or parameter collection and generate a SphereMask inside the material, but obviously that only works if I know how many circles/points in the path I will have.

My thought was to place lights above each tile, and have the material somehow read the light information and multiply it with the whole opacity of the tile, so it would gradually fade out, but AFAIK there isn’t a way to read lighting data from a material.

Does anyone have an idea on how to approach this? Many thanks!!