netbox/netbox/templates/dcim/virtualchassis_add.html

{% extends 'generic/object_edit.html' %}
{% load form_helpers %}

{% block form %}
  <div class="field-group my-5">
    <div class="row mb-2">
      <h5 class="offset-sm-3">Virtual Chassis</h5>
    </div>
    {% render_field form.name %}
    {% render_field form.domain %}
    {% render_field form.tags %}
  </div>

  <div class="field-group my-5">
    <div class="row mb-2">
      <h5 class="offset-sm-3">Member Devices</h5>
    </div>
    {% render_field form.region %}
    {% render_field form.site_group %}
    {% render_field form.site %}
    {% render_field form.rack %}
    {% render_field form.members %}
    {% render_field form.initial_position %}
  </div>

  {% if form.custom_fields %}
    <div class="field-group my-5">
      <div class="row mb-2">
        <h5 class="offset-sm-3">Custom Fields</h5>
      </div>
      {% render_custom_fields form %}
    </div>
  {% endif %}
{% endblock %}