CBRE project management group in NYC

I can't speak for the NYC group, but the groups I have met in smaller markets mostly do tenant fitous. By "entire life cycle of a deal", they probably are referring to a lease, where they would try to provide input from the beginning (lease negotiations), oversee the planning/design, and provide help in managing employees moving into the new space.

CBRE also has a group that does project feasibility, engineering inspections and draw inspections with a heavy concentration on NYC projects (the old IVI International).

Yea this is just another fee business. CBRE PM is typically hired by tenants who do not have real estate construction expertise to manage TI build-outs. They interact with the developer, negotiate and monitor schedule milestones, manage change order requests, and make sure the TI contractor is playing nice. In ground-up development projects, they may play a more active role in negotiating the tenant lease, auditing cost information, etc. Ultimately, though, this is likely a construction management type of job for 3rd party clients.