<ul class="nav nav-tabs">
  <li class="active"><a data-toggle="tab" href="#home">Home</a></li>
  <li><a data-toggle="tab" href="#menu1">Menu 1</a></li>
  <li><a data-toggle="tab" href="#menu2">Menu 2</a></li>
</ul>

<div class="tab-content">
  <div id="home" class="tab-pane fade in active">
    <h3>HOME</h3>
    <p>Some content.</p>
  </div>
  <div id="menu1" class="tab-pane fade">
    <h3>Menu 1</h3>
    <p>Some content in menu 1.</p>
  </div>
  <div id="menu2" class="tab-pane fade">
    <h3>Menu 2</h3>
    <p>Some content in menu 2.</p>
  </div>
</div>

<li class="nav-item">
      <div class="btn-group">
        <button type="button" class="btn btn-primary">{{ session.username }}</button>
        <button type="button" class="btn btn-primary dropdown-toggle dropdown-toggle-split" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          <span class="sr-only">Toggle Dropdown</span>
        </button>
        <div class="dropdown-menu dropdown-menu-right">
          <a class="dropdown-item" href="/get_messages">Messages</a>
          <a class="dropdown-item" href="/get_friend_requests">Friend Requests</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="/logout">Log Out</a>
        </div>
      </div>
    </li>