{%- set items = resource.pages|find_category(post.meta.category) %}
<aside class="aside-container">
  <ul>
    {%- for item in items %}
    <li class="{%- if item.title === post.title %}current{%- endif %}">
      <a href="{{permalink_url(item)}}">{{item.title}}</a>
    </li>
    {%- endfor %}
  </ul>
</aside>