This requirement has the following derivatives:
{% assign canonicals = site.data.canonicals | where: 'type' , 'Requirements' %}
<ul>
  {% for canonical in canonicals %}
    {% assign stub = canonical.type | append: "-" | append: canonical.id %}
    {% assign req = site.data[stub] %}
    {% assign dfs  =  req.extension
      | where: 'url', 'http://hl7.org/fhir/5.0/StructureDefinition/extension-Requirements.derivedFrom' %}
    {% for df in dfs %}
      {% assign dfinstance = df.valueCanonical | split: "/" | last   %}    
      {% if dfinstance == requirement.id %}
        {% assign reqtitle = req.extension 
           | where: "url", "http://hl7.org/fhir/5.0/StructureDefinition/extension-Requirements.title"
           | first %}
        <li><a href="Requirements-{{ req.id}}.html">{{ reqtitle.valueString | escape }}</a></li>        
      {% endif %}
    {% endfor %}	
  {% endfor %}

</ul>