How to get the grid position of an item in a GridLayoutGroup

Hello.
I have a GridLayoutGroup of images, and I need to get the x and y grid position of the one clicked on.

Currently, I do this by putting all of the images in a 2D array, but this seems prone to more ‘off by one’ errors the further you get from top left (0, 0). So I would like to get the exact coordinates of the image from the layout group itself.

Any ideas how?