In situations when you need to allow your customers in a batch, you need to select the "Allow activation by a batch" feature in Queue settings. Based on the value of "Maximum people in batch" that you have set, you will be able to make that many people Active and mark them Complete at a time.
When you turn on this feature, by default the value is set to 1 if "Enable group check-in" is not selected. If "Enable group check-in" is selected, the value of "Maximum people in a batch" gets set to the value of "Maximum people in the group". However you can always change the value of "Maximum people in a batch" to any number greater than or equal to the value of "Maximum people in group".
Please note that this feature is available only in Premium plan and "Maximum people in a batch" value can be set to a maximum of 100.