What you have, more or less, is a two tier hierarchical topology.
Such topologies, whether two tier (e.g. collapsed backbone), three tier (e.g. access, distribution, core), or more tiers (unusual to have more than 3 tiers), are generally build around mostly around star, or tree, topologies. Where they differ, from a pure star topology, is often having multiple core devices (rather than a single root device), or perhaps having additional links between core level, distribution level or even access level. Creating, in principle, possibly a partial mesh topology, but logically, the "layers" are often in a star/tree configuration.
In your diagram, if you were setting up STP, to block accidental loops, for a STP root, likely you would chose either KLr3 or KLr4. But those two devices appear to be the logical "core" of your network, or a logical "root" of a star, or tree, topology.
