Esau married two young women from Canaan: Adah, the daughter of Elon the Hittite; and Oholibamah, the daughter of Anah and granddaughter of Zibeon the Hivite.
So Esau visited his uncle Ishmael’s family and married one of Ishmael’s daughters, in addition to the wives he already had. His new wife’s name was Mahalath. She was the sister of Nebaioth and the daughter of Ishmael, Abraham’s son.
The descendants of Zibeon were Aiah and Anah. (This is the Anah who discovered the hot springs in the wilderness while he was grazing his father’s donkeys.)