You can share and collaborate with other researchers who have Mendeley accounts using the Groups feature.
The Groups feature is on the left-hand menu panel. There are several types of groups you can create:
To create a Group, click Create Group.
The Overview navigation tab shows you the recent activities in the group. Use the Document tab to add/view documents shared to the group and the Members tab to manage membership to the group.
This video shows you how to create and use groups in Mendeley.
Note: This video was released by Mendeley in 2011. The interface for Mendeley may look different from newer versions in use now.