I had a hard time seeing it as well. The groups work by linking them all in a chain and putting two of the other titles from the same hub in small blue links at the end. The part under the vote up / vote down and feedback options of useful, funny, awesome, beautiful. Its as if you are "paging" right or left through the group once you enter into one.
I checked your HP profile and could not find any published hubs. Maybe you are still within the editing stage. Try visiting your hubs and hitting the publish now button near the top :) I will look forward to reading them once they are available. I already fanned you tonight.