An AI query runs on an accelerator, which needs memory stacked beside it, a network to reach its neighbours, a rack and a cooling loop to sit in, and a grid connection underneath all of it. Each of those is a tier, each tier has sub-layers, and each sub-layer has a handful of countries that supply it.
A sixth lens — upstream materials and chokepoints — exists in the atlas but is not yet populated, and is labelled as such rather than filled with guesses.