for those unfamiliar with God broly feats or where he's from:

View: https://www.youtube.com/watch?v=PRPRvJ9Sn9A&pp=ygUZZHJhZ29uIGJhbGwgNEQgcmlkZSBpbnRybw%3D%3D

View: https://www.youtube.com/watch?v=5ETprIIuHGM

he's from a cinema exclusive film called dbz real 4D STB and the movie placement is conventionally placed after the universal tournament arc. he clowned an SSB goku and vegeta in that movie till goku fused with the RL-esque audience to become God fusion goku. he later on appeared in heroes so he's also canon to that verse https://www.youtube.com/watch?v=kqwqP8bPYIk

so it's only supposition my part but there is no explanation for how he come back in that movie and even goku and vegeta are shocked about it. so he either got revived by some magical means or he survived M10 events in the same vein as M8.