using_group_by_drop.html

<div class="blog-archive">
    <h2>All entries</h2>
    <ul id="blog-archive">
        {% for children_by_year_then_month in object.children.group_by.published_at_beginning_of_year_then_month %}
            {% assign year = children_by_year[0] %}
            {% assign children_by_months = children_by_year[1] %}
            <li class="year" id="year_{{ year | date: "%Y" }}">
                {{ year | date: "%Y" }}
                {% for children_by_month in children_by_months %}
                    {% assign month = children_by_month[0] %}
                    {% assign children_in_month = children_by_month[1] %}
                    <ul>
                        <li class="month">{{ month | date: "%B" }}
                            <ul>
                                {% for child_in_month in children_in_month %}
                                    <li>
                                      "{{ child_in_month.name }}":{{child_in_month.path}}
                                    </li>
                                {% endfor %}
                            </ul>
                        </li>
                    </ul>
                {% endfor %}
            </li>
        {% endfor %}
    </ul>
</div>