Can. 1248 §1. A person who assists at a Mass celebrated anywhere in a Catholic rite either on the feast day itself or in the evening of the preceding day satisfies the obligation of participating in the Mass.
It is the time that a Mass is said, not the readings, that make it qualify. So you can fulfill your Sunday obligation by attending the Christmas Vigil (not the midnight Mass). However, there are two separate obligations, you cannot fulfill them both with a single Mass. You must attend two, even if they’re both liturgically Christmas Masses.