How to create promotion life event

Summary:

Content (please ensure you mask any confidential information):

Hello,

We want to check if an employee who might be of band 1 is being promoted to band 2 , how does the promotion life event work ? do they get to edits the options values ? or do the system calculates accordingly ?

Version (include the version you are using, if applicable):

24c

Code Snippet (add any code snippets that support your topic, if applicable):