{% load wagtailcore_tags %}
{% for item in pages %}
    {% if item.children %}
        <li class="dropdown">
            <a href="{% pageurl item.page %}" class="dropdown-toggle">{{ item.page.title }}</a>
            <ul class="dropdown-menu" data-navigation="dropdown-menu">
                {% for child in item.children %}
                    {% if child.children %}
                        <li class="dropdown-submenu">
                                <a href="{% pageurl child.page %}">{{ child.page.title }}</a>
                            <ul class="dropdown-menu">
                                {% for sub in child.children %}
                                <li><a href="{% pageurl sub.page %}">{{ sub.page.title }}</a></li>
                                {% endfor %}
                            </ul>
                        </li>
                    {% else %}
                        <li><a href="{% pageurl child.page %}">{{ child.page.title }}</a></li>
                    {% endif %}
                {% endfor %}
            </ul>
        </li>
    {% else %}
        <li><a href="{% pageurl item.page %}">{{ item.page.title }}</a></li>
    {% endif %}
{% endfor %}