If you want to add one more level of ranking according to the Product ID , that can easily be added. At present , your data does not show that this is necessary.
Thank you both for your responses, I can see that you are going to be able to solve this puzzle.
I realized that I didn't explain one part of my issue very well. I do want to group the results by product ID so that the rankings should only compare items with the same ProductID. The example I posted actually shows what the required output should be. (The Rank column is the needed output)
So the output would have these requirements:
A separate ranked set for each unique ProductID
Within a ProductID all priority one rows would come before any priority two rows
Within a ProducutID priority one rows would be ranked oldest to newest and then priority two rows would continue the ranking set, also oldest to newest