Immigrants from Geramny

I was told that TWO of my Geller family moved from Germany to Transylvania probably in the 1600s , but haven't known where to look.  They do show up in mid Hungary in the early 1700s, but don't know where any of them came from in the two countries. Been search for past 50b years with no luck, but then Transylvania has been overrun so many times!  Any suggestions?

Don't know how this works yet, so doing my best for a first timer.