I can see from your screenshot the data is ordered - are you wanting this list to be numbered (ranked) 1 - x based on this sort? Have you seen the quick table calculation of Rank? Quick Table Calculations - Tableau
If you're looking for something more, then it would be useful if you could provide a bit more details about what you're trying to do, and provide a packaged workbook showing what you've got to and screenshots/examples of what you're trying to get to . The packaged workbook can contain sample data if you're unable to provide your exact data. Please refer to Packaged workbooks: when, why, how for further details on why we ask for this and how to do it.
Any feedback on this? Have you managed to solve the problem? Please post an update and if my response helped in any way please mark as correct or post your own fix and mark as correct, so the thread can be closed down.