The Permissions section within a staff profile shows the permissions and roles ever given to the staff member.
To add another Business Role onto the profile click on the (+) sign next to 'Current business roles'.
Choose the new business role from the slide over and click 'Assign Role'.
To add a specific permission to a staff member go to 'Permissions' on the left-hand side of the profile and click the green 'Ad Hoc Permissions' button.
Choose the specific permission from the slide over and click 'Assign permissions'.
For more information, you can watch a video about this topic here.