Germany has three national leagues (as opposed to England's five), and there are two 'second' teams in 3.Liga (Stuttgart and Dortmund).
After that, it's regional leagues, with attendances about on a par with Conference South level.
Worth looking at this article from seven years ago about problems with B Teams in Germany.
http://www.wsc.co.uk/the-archive/923-Europe/598-the-killer-bs