Assign attendee group automatically to “Billing item” on registration

To link a billing item to multiple group, you first have to enable the setting “Billing item link to”:

Goto: Reg.Site->Billing module->Payment settings->General settings

Set billing item link to “Group” and save the changes.

Goto:>Billing module->Billing items

Select or create a billing item. Select link to “Attendee groups” and then you can assign multiple group to the billing item as displayed below.