costapy/templates/basic_bootstrap/html/topnav.html

<nav class="navbar navbar-expand-lg navbar-dark bg-dark fixed-top">
  <a class="navbar-brand" href="/">${GV_title}</a>
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>
  <div class="collapse navbar-collapse" id="navbarSupportedContent">
    <ul class="navbar-nav ml-auto">
      % for item in menu:
        % if any(role in item['roles'] for role in user_roles):
          <li class="nav-item ${'active' if item['name'] == active_page else ''}">
          	<a class="nav-link" href="${item['href']}">${item['name']}</a>
          </li>
        % endif
      % endfor
    </ul>
  </div>
</nav>