Here's the list of Bomin's friends outside Golden Child fam
Astro: Sanha
WannaOne: Daehwi
The Boyz: Hwall, Sunwoo, Eric
D'Crunch: Minhyuk
Ateez: Wooyoung
Stray Kidz: Hyunjin
Trcng: Taeson
NCT: Jeno (his newest friend haha)
PS: he's basically friends with all the boyz members.