Mapping hierarchical urban boundaries for global urban settlements

•We proposed a mapping model to consistently identify hierarchical urban boundaries (HUBs) for global urban settlements.•Our HUBs are physical boundaries supported by remote sensing, which are more objective and internationally comparable.•We generated a global vector database of HUBs based on 30-meter data and reinvestigated global urban settlements.•We pioneeringly confirmed the universality of the Rank-size rule in the urban systems of 47 countries by using HUBs.•We showed the potential of HUBs to measure the characteristics of urbanization at the macro and micro levels.