_layouts/libs_ul.html

<ul class="sub-list list">
  {% for wf in site.data.helper_libs %}
    {% assign wf_url = wf.url | prepend:"/wf_states/" | append:"/" %}

    {% if wf_url == page.url %}
      {% assign c = "active" %}
    {% else %}
      {% assign c = "" %}
    {% endif %}
    <li class="{{ c }}"><a href="{{ wf_url }}">{{ wf.title }}</a></li>
  {% endfor %}
</ul>