ant-design/site/templates/aside.html

<aside class="aside-container">
  <ul>
  {%- set items = resource.pages|find_category(post.meta.category) %}
  <li>
    <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>
  </li>
  </ul>
</aside>