Planning boards propose zoning changes.
City council or in towns, town meeting affirms or rejects.

The Zoning Board of Appeals generally deals with nonconforming properties in terms of zoning, and some kinds of special permits for buildings.

Massachusetts now has a regional zoning requirement for multiunit housing in MBTA Municipalities, near stations.

See this summary:

Mass. Dept of Housing and Community Development.
https://www.mass.gov/info-details/multi-family-zoning-requirement-for-mbta-communities