Checking Availability for Groups

In the Booking/Invoice screen, the Check Availability link can be clicked from the Items dropdown so long as the booking dates have been entered.  This will list all the individual items and their availability.

Using the Availability screen (via the Availability button on the main screen or via Sales/Hire > Availability) you can click the Grouped option on the Itemised/Grouped toggle button which appears to the right of the Category. 

This will list a one liner for the item group with a total quantity for hire, and will show the quantity hired or available in the calendar.