There isnt one. You have to request for a b- billet and its really up to your current manager if they want to lose you. i found that allot of managers gatekeep special roles and there is definitely favorites and tenure to contend with to get them but if generally you'll get them so long as you aren't transferring departments. Note that most of these roles wont increase your pay.

Walked in. They asked me what shift I wanted. Took my picture and sent me on my way. I started less then a week later. The lines for the interview were long but the hey had a lot of interviewers