getting tiles relative to a specific tile in a Grid of tiles

Hi, thank you for your support.

i’m facing a situation in blueprint where i have a grid of tiles and i created an array of tiles indexed with integers from 0 to 120 so i have 120 tile ,

Now what i want is to make the tiles (that are allowed for my static actor to move to ) glow , so how can i start thinking about the logic to get the indexes of the tiles that sits straightforward relative to a certain tile index ??, or in any direction i want ,basically what i’m talking about is like a chess board and setting the allowed moves for a certain piece like Knight .

what i want resembles exactly the default chess game in win 7 where they are setting the tiles allowed to glow picture below…