nav-item nav-link disabled
html bootstrap5 Sample
<ul class="nav nav-pills">
<li class="nav-item"><a class="nav-link active" href="#">アクティブ</a></li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" data-toggle="dropdown" href="#" role="button" aria-haspopup="true"
aria-expanded="false">ドロップダウン</a>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">リンク1</a>
<a class="dropdown-item" href="#">リンク2</a>
<a class="dropdown-item" href="#">リンク3</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">その他リンク</a>
</div>
</li>
<li class="nav-item"><a class="nav-link" href="#">リンク</a></li>
<li class="nav-item"><a class="nav-link disabled" href="#">無効</a></li>
</ul>
<ul class="nav nav-tabs">
<li class="nav-item"><a class="nav-link active" href="#">アクティブ</a></li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" data-toggle="dropdown" href="#" role="button" aria-haspopup="true"
aria-expanded="false">ドロップダウン</a>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">リンク1</a>
<a class="dropdown-item" href="#">リンク2</a>
<a class="dropdown-item" href="#">リンク3</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">その他リンク</a>
</div>
</li>
<li class="nav-item"><a class="nav-link" href="#">リンク</a></li>
<li class="nav-item"><a class="nav-link disabled" href="#">無効</a></li>
</ul>