The Ubermensch as described by Nietzsche was not the Superman of today or the Perfect Aryan of Hitler's vision.
The Nearest version in literature was the Pulp adventuring character Clarke "Doc" Savage.
The Ubermensch is the person who has achieved their full potential as a human being, one who lives on an optimised scale, educated to the highest degree they are capable of, as fit as their physically allows, with a mind unhindered by social or religious programming, but driven by logic and reason, tempered by compassion.

The Ubermensch therefore is not a thing it is an ideal to be striven for, and that those that who get closest to that ideal should be the natural leader of those happier and more productive in the environment of "the herd"

It was a member of a super race. Hitler spoke of this of course.