JSFiddle - React, Tailwind, and code Playground

HTML

<ul class="dropdown">
    <li>Normal</li>
    <li>Normal
        <ul>
            <li>Normal</li>
            <li>Green</li>
        </ul>
    </li>
    <li>Red</li>
</ul>

CSS

ul.dropdown > li:last-child {
   color: red;
}

ul.dropdown > li > ul > li:last-child {
   color: green;
}