Use $Setup to access hierarchical custom settings and their field values using dot notation. For example, $Setup.App_Prefs__c.Show_Help_Content__c.
Custom settings of type “list” aren’t available on Visualforce pages using this global variable. You can access list custom settings in Apex.
<apex:page> <apex:inputField value="{!usr.Workstation_Height__c}"/> <apex:outputPanel id="helpWorkstationHeight" rendered="{!$Setup.App_Prefs__c.Show_Help_Content__c}"> Enter the height for your workstation in inches, measured from the floor to top of the work surface. </apex:outputPanel> ... </apex:page>