<nav class="menu">
  <span class="menu-heading"><%= octicon 'rocket' %> Site Admin</span>
  <%= link_to 'Search', stafftools_root_path, class: 'menu-item selected' %>
</nav>

<nav class="menu">
  <span class="menu-heading"><%= octicon 'code' %> Developer Tools</span>
  <%= link_to 'Features', stafftools_flipper_path, class: 'menu-item' %>
</nav>

<nav class="menu">
  <span class="menu-heading"><%= octicon 'rocket' %> Site Admin</span>
  <%= link_to 'Search', stafftools_root_path, class: "menu-item #{'selected' if current_page?(stafftools_root_path)}" %>
</nav>

<nav class="menu">
  <span class="menu-heading"><%= octicon 'code' %> Developer Tools</span>
  <%= link_to 'Features', stafftools_flipper_path, class: 'menu-item' %>
</nav>

Make stafftools search link selected only on search page
Make stafftools search link selected only on search page

Add selected class to search link only on stafftools_root page
