Not sure how legit this is, but according to SpoilerTV, these are the titles of the first three episodes of season 4:
- Brooklyn Nine-Nine – Episode 4.01 – Coral Palms, Pt. 1
- Brooklyn Nine-Nine – Episode 4.02 – Coral Palms, Pt. 2
- Brooklyn Nine-Nine – Episode 4.03 – Coral Palms, Pt. 3