how to apply prompt based on description and send ID to analysis for calculation

Summary:

I have Period Name as Dashboard prompt but period Number should be returned based on Period Name selected in dashboard prompt to underlying analysis.

eg., when I select Jul-21 in drop down of dashboard prompt, then Period Number 6 should be returned to my analysis for further calculations in the criteria.

Content (required):

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

oac

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