Short answer
HubSpot's KB: Restore CRM changes rolls records back to an earlier point within the last 14 days, undoing updates from workflows, imports or manual edits. For manual changes you can limit it to certain properties or one user. A workflow's property changes can also be restored from the workflow editor.
1. Where it is
The contacts index actions in my demo portal.

2. Deleted records
See restoring deleted records.