You can create a group appointment by creating an appointment as usual, then adding multiple patients in the appointment form.
Click Schedule > Calendar.
Create an appointment by clicking on the appointment time on the calendar.
Add a patient to the appointment.
Click Add Another Patient below the patient details. The form will expand to allow for another patient. Add the additional patients' details.
Repeat Step 4 for all additional patients.
Complete the rest of the appointment details and click Submit.