From the Dashboard, click Configure.
On the left hand side select Question Groups under Booking Settings > Booking Questions.
Click Create New.
Select the Question you want this Question Group to ask.
Click Create Another to add another Question to the Question Group.
You can also use the Position arrows to rearrange the order the questions will appear.
To apply a Question Group to a certain Service, Resource, Event, or Class, from the Dashboard, click Configure.
Navigate to the desired Service, Resource, Event, or Class menu. (This tutorial chooses Services.)
Navigate the the Question Set dropdown menu (Under Advanced Settings for Services) and select the Question Group for that Service, Resource, Event, or Class. (The Question Set dropdown menu will be located in different locations depending on if its a Service, Resource, Event, or Class.)