Hi @BWitcher,
There are a few time tracking apps which integrate with HubSpot, like PSOhub (time tracking), Clockify(picks up the name of ticket records), TMetric (timer button for HubSpot tasks) or Hourstack (also for tasks) which seem to work well with HubSpot. You would have to check whether these apps fulfill your exact requirements and allow you to see all employee activity by time.
If a HubSpot integration is not a must, I’d recommend Toggl.
Best regards