How do you allow a role to assign other users roles - but only specific roles? I'm creating a "level'ing" role system on my page. At a certain role (Full Member) the user must be able to assign someone with the role level 5 the new role level 6 manually once a dialogue is complete. 

How can you do this?
I think Role Delegation is what you're looking for.


  For each role, Role Delegation provides a new assign ROLE role
  permission to allow the assignment of that role.