LinkedIn have recently changed groups to make it a little harder to find the “Leave Group” button.
As a sourcer you probably swap groups all the time. This lets you use the 50 group limit to maximise the size and relevancy of your network. It also gives you the ability to send messages to those people that share a group with you.
How to leave a LinkedIn Group:
Go to the Group page:
Under the More… tab you will find My Settings
The Leave Group button is at the bottom on the right hand side.