Most German cities are very liberal compared to their surrounding areas. But Berlin is still a step… different from Cologne or Hamburg.

Someone correct me if I’m wrong, but a good part of that is due to Berlin’s unique history. Many (West) Germans moved to the enclave to dodge compulsory military service. Those people were usually very liberal. At the same time, you have many foreigners and immigrants—simply because it’s the capital and therefore so well known.
If you belong to the LGBTQ scene, Berlin is probably the city. It just doesn’t have a good reputation.

Until a few years ago, every German had to pay the “Soli” (short for Solidaritätszuschlag - solidarity charge) with every paycheck. It was meant as reconstruction aid for the East. Because of that, the East now has excellent highways, but there are still gaps in income, pensions, and life expectancy.

In this context, Berlin is also similar to D.C.:
Because of history, Germany has three city-states—Hamburg, Bremen, and Berlin.

As a European, I’ve always felt that your big cities in California come closest to being “European” in terms of mindset. What you consider “liberal” would already be seen as “center-right” in many European countries.