"hubris" (hu - bris) comes from the IndoEuropean roots
ud - gwer (out - heavy).
gwer
also evolved into both "brute" and "krieg" (cf. Blitzkieg) by differing
routes. In the former we see the "br" of "hubris".
ud is supposed to be the root which evolved into the Greek prefix "hy".
"uber" comes from the root
uper (over).
Since the "u" of hubris came from a different root than the "b", I doubt that "hubris" is related etymologically to "uber".
CJ