From the side panel menu, under Healthy Culture, click on "Cultural Leadership Framework"
From the table that appears on the right-hand side, find the Cultural Leader and select the Edit button to the right of their name:
Select "Add Person to Cultural Cohort" and pick from the drop-down menu:
When finished, hit the "OK" button
What happens next?
The person you selected to be in the Cultural Cohort will now appear in the table under the Cultural Leader section: