{% with page.get_children as children %}
    {% if children %}
        <div>
            <button class="show">In this section</button>
            <button class="hide">Close</button>
        </div>
        <ul>
            {% for child in children %}
                <li><a href="{{ child.url }}">{{ child.title }}</a></li>
            {% endfor %}
        </ul>
    {% endif %}
{% endwith %}