Select all nodes that reference the current node
You could do this using views.Create a view where under 

Fields you select your group as Node, Under that choose Title.

For Filters select Node Type, Operator: Is one of and select Clinic content type.

Under Arguments select your group as Content. Under that choose Clinic_group (the node reference field).


You can add additional parameters to your view like Number of items to display, more fields like Node: Body and maybe a filter that Node: Published, select yes. 

To see a preview, under live preview give the arguments as node number and click Preview. 

Hope this helps!