blog/_includes/sidebar/common-list.html

{%- if include.keys -%}
  {%- assign keys = include.keys -%}
{%- endif -%}

{%- if include.field -%}
  {%- assign field = include.field -%}
{%- endif -%}

<div class="common-list">
  <ul>
    <li>
      <a href="{{ '/index.html' | relative_url }}">
        All<span>{{ site.posts.size }}</span>
      </a>
    </li>

    {% for key in  keys %}
      <li>
        <a href="{{ url }}#h-{{ key }}">
          {{ key }} <span>{{ site.posts | where: field, key | size }}</span>
        </a>
      </li>
    {% endfor %}
  </ul>
</div>