Assigning a Leader Role

How do we assign a 'Leader' role to a new employee? I am an administrator and I have been looking through the Member Management and Platform Management cockpits, but I don't see any options for this.

 

He has been assigned a Mechanical Designer role, but can only login as an "Author" and with the option for "Leader" not being shown. He ultimately needs to be able to export content from the platform.