Figure 2

Schematic illustration of the level-by-level calculating process on a hierarchical structure for (a) a star-like multilayer system and (b) a tree-like multilayer system. The gray circle denotes the network layer at the top level.

Schematic illustration of the level-by-level calculating process on a hierarchical structure for (a) a star-like multilayer system and (b) a tree-like multilayer system. The gray circle denotes the network layer at the top level.