Ok, then it’s WPO ( world position offset ). You can move the whole mesh up and down with that. So if you have a selective mask, then you can just move parts of it up and down.
You could also use a simple B&W texture ( possibly left and right half, or possibly a B&W quad ) with UV manipulation to move just one of them…
Just looking at your spec again, it would either be a square mask with an outline and UV fiddling, or a mask that looks like the row of cubes, multiplied by copies of a single square. Something like that 