side_nav.html

{% if page.site_nav_category %}
{% assign menu_items = (site.pages | where: "site_nav_category", page.site_nav_category) | sort:"site_nav_category_order" %}

<nav class="tac-navigation mdl-navigation">
    {% for menu_item in menu_items %}

    {% unless menu_item.is_site_nav_category %}
    <a class="mdl-navigation__link mdl-js-ripple-effect{% if page.url == menu_item.url %} mdl-navigation__link--current{% endif %}{% if menu_item.is_site_nav_category2 %} tac-site-nav-category{% endif %}"
       href="{{ menu_item.url | prepend: site.baseurl }}">{{ menu_item.title }}
        <div class="mdl-ripple"></div>
    </a>
    {% endunless %}
    {% endfor %}
</nav>
{% endif %}