I don't think you can really do it accurately on HP itself. The only way I can think of doing that is by picking the individual hub you want to check and looking at the stats. The graph underneath has the daily views, but can be hard to read if your hub is older as the data is squashed or if you get a lot of traffic.
The best way to check is if you have set your account up in Google Analytics. If you added you're HP url there then it tracks all your individual pages and you can go back as far as you like (or as far back as when you added the subdomain to the Analytics account) and get your daily traffic figures for each hub.
When you log into your analytics account, go to Traffic Sources. Once you click on that click on the option that appears underneath that which says Overview. Now it will show you the top 10 keywords bringing traffic to your pages. There will also be a pie chart. Underneath the pie chart is the option that says Landing Page. Click on this and it will show you your top 10 landing pages by visitors. If you want to see more you can click on the individual pages and get traffic stats for them. If you want more info on less successful hubs then click the view report button in the bottom right of the page. Now you can use the arrow keys on the bottom right of the page to find the hub you were specifically looking for.
Analytics can measure just about anything you want. If you haven't already added your HP subdomain to Google Analytics then I would suggest you do. It's free and it's really simple to set up. It's constantly being improved and has so many great features and makes it easy to figure things out with graphs and pie charts etc.