Using the sitemap in Middleman

gistfile1.erb

<% if current_page.parent %>
  <h2>Parent</h2>
  <ul>
    <li><%= link_to current_page.parent.data.title, current_page.parent %></li>
  </ul>
<% end %>

<h2>Children</h2>
<ul>
<% current_page.children.select { |p| p.ext == ".html" && p.data.title }.each do |resource| %>
  <li><%= link_to resource.data.title, resource %></li>
<% end %>
</ul>

<h2>Siblings</h2>
<ul>
<% current_page.siblings.select { |p| p.ext == ".html" && p.data.title }.each do |resource| %>
  <li><%= link_to resource.data.title, resource %></li>
  <% unless resource.children.empty? %>
    <ul>
      <% resource.children.select { |p| p.ext == ".html" && p.data.title }.each do |child| %>
        <li><%= link_to child.data.title, child %></li>
      <% end %>
      </ul>
  <% end %>
<% end %>
</ul>