Should be easy enough to create a shortlist. There's only 70 German companies with a market cap of greater than $5bn. Doubt Buffett would go lower than that.
Allianz is a high quality insurer that consistently writes at a combined ratio of under 100. Trades at 10x earnings, buys back stock. Anaemic growth however.
Adidas has improved their business in the last few years, increased margins, now buying back stock. Doesn't look much different than something like Nike, which makes me think this one isn't likely. You'd think if Buffett was interested, he'd stick with the ones he knows better.
Knorr Bremse is quite a bit smaller than the above, but it's reasonably priced, it's got some growth, reasonably stable operating margin. They don't buy back stock, but they don't issue it either. We know Buffett likes railways, why not train makers too?