Sales Rep Part of 2 business units, but can't report on activity of extra team/business unit

We utilize HubSpot’s Business Unit feature.

 

We have a sales rep who works across 2 business units. This means he sends email, has meetings, and creates deals across 2 business units and 2 sales pipeline.

 

Tracking deal activity isn’t difficult because it relies on the Pipeline filter when reporting.

 

However, we currently have no way of tracking his activity between the 2 business units. Every email or call he logs is automatically categorized under his “primary” business unit, even if its in relation to the other business unit.

 

Am I missing something? Is there a way I can view his activity for only a specific business unit? Is there a way to make sure that certain activities are logged/categorized under a specific business unit?

 

Thank you.