title: How to loop through YAML frontmatter content for use in Liquid? (Jekyll)
body: <p>I'm trying to loop through some values in my frontmatter's <code>sidebar</code> property to use in some Liquid loops that also make use of YAML, but it's not working. </p>
  
  <p>Here's the code:</p>
  
  <pre><code>---
  sidebar: [a, b, c]
  ---
  
  {% for sidebar in page.sidebar %}
  {% for entry in sidebar.entries %}
  ...
  </code></pre>
  
  <p>I want the code to use a.entries, and then b.entries, and then c.entries, but it's not working. Is that because all the YAML processing happens at once, and then the Jekyll pipeline process moves on to HTML or something?</p>