The article explores how cities in Germany have developed into multi-core metropolitan regions, either around a central city or through neighboring metropolises interacting more closely. The researchers investigate whether these regions share global functions or if they are concentrated in a single city. By analyzing the locations of global advanced producer service firms, they found that different cities within these regions play important roles in the world city network. This shows that Germany's urban system exhibits both types of polycentricity, with multiple cities contributing to global functions.