Depends if you mean culturally or legally.
DH and I are both Scottish (which is problematic anyway, and we are actually British - ‘Scottish’ only exists culturally, not legally). Both our children get British nationality from us.
DS1 was born in NZ. The rules of nationality there mean that he is granted NZ citizenship from birth: he has a NZ passport. So he is British and a New Zealander.
DS2 was born in France. Different rules here: he does not automatically receive French citizenship from being born here. He can claim it when he turns 13, but for now he’s British only.
culturally though… DH and I are Scottish - a nationality which does not legally exist. No Scottish passports. We haven’t lived there for 20 years, but that’s where our roots, family, history are, that’s where our accents come from, that has shaped our view of the world.
Both DSs are Scottish in a similar way, through frequent visits, family connections, stories, meeting other Scottish people here, living in a bit of a bubble as many immigrants do - thought neither of them have lived in Scotland. They certainly identify in that way: if you ask them, they’ll tell you they are Scottish.
we are all culturally British as well, I guess but I have a less clear idea of what that feels like.
DS1 would describe himself as a Kiwi, but he has nothing other than a passport to back it up. We left NZ when he was 4 months old and haven’t been back. We don’t have any family there. He’s very French in a lot of ways - all his schooling, his friends, his life has been French since he was a baby (5 months old when we came here). But he’s obviously not ‘propert’ French, and he wouldn’t describe himself as French.
DS2 is adamant that he isn’t French. He’s Scottish, and that’s good enough for him 😁. Yet ironically he’s likely to get French nationality before any of the rest of us do, just by the way things have worked out.
c’est compliqué.