How do I do a simple GROUP BY?
I am not 100% sure but I would suggest you simply do the following:


Choose Format = Table
Then click on the settings for Table
Change the grouping field to the "hash" field




Then aggregate the results based on the destinations. 

However, when you use the redirect module in Drupal 7 there is a field available called "Redirect: Clicks". I wonder if this may help you.

I hope this may helps.