In Greek mythology, Menoeceus the Elder was a Theban of Spartoi blood, father of Creon and Jocasta (and so grandfather and father-in-law of Oedipus). Hyginus has him leap from the walls to end the Sphinx's plague. Distinct from his grandson Menoeceus son of Creon (atlas id menoeceus-young), who sacrifices himself during the Seven against Thebes.
Adapted from Wikipedia, "Menoeceus" · CC BY-SA 4.0
I.Father of Creon and Jocasta
Menoeceus belongs to the Cadmean house through the Spartoi — the armed men born from the dragon's teeth. Standard genealogies make him father of Creon, the later regent, and of Jocasta, wife first of Laius and then, unwittingly, of Oedipus. Through that double link he stands behind the Theban tragedies of Oedipus and Antigone.
Some notices also give him a daughter Hipponome. Parentage is variously tied to Pentheus and Echion's line among the sown men.
II.Sacrifice and homonym
Hyginus (Fabulae 67) has Tiresias declare that the Sphinx's scourge will end if one of the dragon's blood dies for the city; hearing this, Menoeceus throws himself from the walls. Other traditions attach a Theban self-sacrifice to Creon's son of the same name during the Argive siege — Pausanias visited that younger Menoeceus's tomb, where a pomegranate tree grew with blood-red fruit.
The atlas keeps menoeceus (Elder) and menoeceus-young as separate nodes so the Sphinx-era and Seven-era sacrifices are not collapsed into one star.