JSFiddle - React, Tailwind, and code Playground

HTML

<ul class="pr">
    <li>
        item1
        <ul>
            <li>item1_1</li><li>item1_2</li>
        </ul>
    </li>
    <li>
        item2
    </li>
    <li>
        item3
        <ul>
            <li>item3_1</li><li>item3_2</li>
        </ul>
    </li>
</ul>

CSS

ul.pr {
    padding: 0 0 20px 20px;
    float: left;
}

ul.pr > li {
   position: relative;   
}

ul.pr > li > ul:after {
    content: '\25cf';
    position: absolute;
    top: 0;
    left: -15px;
    color: red;
}