Hi Nicholas,  
 " Agent Advanced Operation " Permission will be at the " Applications " tab in "Roles" section tied to the user. Once you are in the "Applications" tab, look for " Default Permissions " and then click on " Edit" . It will open a new window " Edit Permissions ". The very first Permission listed in the window will be " Agent Advanced Operation"  
 Administration - Roles - Applications - Default Permissions - Edit 
 Also, attaching an image for your reference. Hope, this helps. 
 Thanks, 
 Sunil 
    
						
					
					... View more