The Role field is a dropdown next to the person's name in the task list.

Once roles are set, you can use filters to view items that include tasks with a specific role. 

Enabling Roles

To enable roles, follow the steps which are detailed here

Assign Roles

  1. Make sure that the "roles" feature is enabled
  2. Go to the Initiative Settings page
  3. Select the 'Members' section from the left menu
  4. Click "Edit" located next to a member's name to choose/add roles.