There is a user security permission associated with each status. These permissions only apply to users who have the permission Manage Competencies; users who do not have this permission will only see approved competencies and their children.
In the interface, users can only see the competencies whose status they have permission to see.
For example, if a user only has permission to see In Review competencies, then on the Competency List page they will see:
In addition, there is a separate permission Set Competency Status that controls whether a user is able to change the status of a competency.
Using these permissions together you can establish a workflow process that controls which users have access to competencies at each stage in their life-cycle, and who has the authority to move a competency forward to the next stage (or bump it back to a previous one) by changing the status.