QuantumListing Groups are a new feature. You access them through the groups menu on the sidebar on the left side of your profile page.
You can start your own group with colleagues that are already on QuantumListing and also invite others to join QuantumListing and be a part of your group. You can also join other groups that are open to the public by searching for them from your profile page.
Groups make it easier to look through your colleagues profiles and listings.
Join a group by clicking on Groups in the left hand side bar on your profile page. Then click on My Groups. Search for a group you want to join and then hit the + sign. Click Yes when you are asked if you want to join the group.