navbar navbar-expand-lg navbar-dark bg-primary

  <nav class="navbar navbar-expand-lg navbar-dark bg-primary">
    <a class="navbar-brand" href="#">ブランド</a>
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent2"
      aria-controls="navbarSupportedContent2" aria-expanded="false" aria-label="ナビゲーション切替">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarSupportedContent2">
      <ul class="navbar-nav mr-auto">
        <li class="nav-item"><a class="nav-link" href="#">リンク1</a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク2</a></li>
        <li class="nav-item"><a class="nav-link" href="#">リンク3</a></li>
      </ul>
    </div>
  </nav>