JSFiddle - React, Tailwind, and code Playground

HTML

<ul class="users">
    <li>
        <a href="#">Sign in</a>
        <ul class="userMenu">
            <li><a href="#">Slider menu item</a></li>
            <li><a href="#">Slider menu item</a></li>
            <li><a href="#">Slider menu item</a></li>
            <li><a href="#">Slider menu item</a></li>
            <li><a href="#">Slider menu item</a></li>
        </ul>        
    </li>
</ul>

CSS

.users > li {
    position: relative
}
.users > li > a {
    background:yellow;
    background:rgba(255,255,0,0.5);
    float:left;
    padding:1em;
    position:absolute;
    width:200px;
    z-index: 1
}

.userMenu {
    background:grey;
    position:absolute;
    top:2em;
    left:0;
    width:120px;
}