Green’s Dictionary of Slang

(US black teen) rising up, coming up, emerging vigorously.

2000		P. Beatty Tuff 36: He didn’t embellish [...] his exploits, talking in pipe-dream slang about him and the crew ‘coming up,’ ‘blowing up,’ ‘bubbling,’ and ‘living large’.
2003		A. Newitz ‘Bay Area Sl.’ on Berkeley University Amer. Studies 102 Course Website 🌐 Bubbling – Rising up, coming up. Bubbling under.