Can you use PieSync to sync HubSpot portals with one another?
Yes - you can use PieSync to sync two or more HubSpot portals with one another.
Contacts or Companies can be kept in an active sync across multiple portals, using complex sync rules to keep the overview. Important to note: this will not sync contact-company associations, nor will it sync timeline events.
Other ways to sync portals
Check out the Portal Replicator if you only need a one-time complete sync of portals instead of a continuous sync.
For a more comprehensive, continuous sync of more than just contacts and companies, including timeline events, consider Lynton's Multi-Portal Sync