Compensation Plan - job view on proposed job

Summary:

One of the compensation plans we are creating is called CompCycle, in which Managers will promote their employees. 

Content (required):

The issue is that they don't want Managers to be able to see jobs above them in the Proposed Job combobox. 

How do I know the Job is above his? By level  

Any other sugestion?

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

23B

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