Thomas Wayne Junior. Bruce N. Wayne. Never heard of these two anecdotes in the Wayne legacy?
On Earth-One, Thomas and Martha Wayne had two sons. The younger, and more famous, was named Bruce. He would see his parents murdered and avenge their deaths as the Batman. However, he had an older brother, Thomas Junior, mentally disabled due to an accident as a youth, and was housed in Willowood Asylum where he remained until later he was used as a pawn as the Boomerang Killer. Eventually, Junior perished while saving his younger brother's life.
On Earth-Two, Bruce N. Wayne was the first cousin of that world's Batman, once removed, and a private investigator. Visiting from his native California, Bruce N. was disgusted that his commonly named kinfolk was a do-nothing rich playboy, until he deduced that the younger Wayne was the alter ego of Batman. However, Batman tricked his cousin into rethinking this theory at the conclusion of a criminal case, and so Bruce N. returned to the West Coast none the wiser.