Determining If a Record Is the Most Recent in the Sheet

Hello Everyone,

I am working to try and find a function that will help me determine if a specific record is the most recent within the sheet. I have a sheet that holds a large amount of historical data, and at a given snapshot in time, there could be multiple versions of the same record listed. A field 'systemmodstamp' lets me know when the last change was made. The problem is that these records are randomly placed within the sheet. I need a way to see if the opportunityid in that cell has a duplicate or repreated entry, and if the system mod stamp is the greatest of its duplicates. I'll include a screenshot of some of the data and what I am looking for from the outcome.

Any advice would be greatly appreciated,

Thanks