Global political trends is a pseudoscientific phenomenon.
I'm inclined to say that Germany became much more polarized with the concurrent rises of the AfD and the Greens. If anything, western Germany is moving to the left, while eastern Germany is moving to the right.
What about south Germany? It may be that my study of German politics, being predominantly based in the 1871-1932 period, has given me an antiquated view of German political culture, but I seem to think of Germany as Northern, with the subsections or West/East, and Southern - Baden, Wurttemberg, and Bavaria.
Baden-Württemberg has now a Green minister-president, although a pretty centrist one who's also supported by a lot of former CDU voters.
I'd say southern Germany is located politically somewhere between eastern Germany and western/northern Germany. Southern Germany is also trending towards the Greens now although their brand of Green politics is definitely a bit less leftist than in the rest of the country (see the Baden-Württemberg remark above).
I also think that eastern Germany is actually moving from the Left Party's kind of left-wing populism towards the AfD's kind of right-wing populism now while neither the Left nor the AfD is particularly strong on southern Germany. The south is still largely a CDU/CSU stronghold with the Greens being on the rise there.
This divide between East and South can be explained culturally. The East is predominantly an atheist region, while the South is still heavily influenced by Catholicism. Hence the South's affiliation with old school religion-derived conservatism and the East's affiliation with the more secular "New Right". Coincidentally, the aforementioned Green minister-president of Baden-Württemberg happens to be a member of the Central Committee of German Catholics.