JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#" id="cities-button">Град</a>
<div id="cities">
    <ul>
        <li>София</li>
        <li>Пловдив</li>
        <li>Варна</li>
        <li>Бургас</li>
    </ul>
</div>

CSS

#cities-button {
    font-size: 20px;
    text-decoration: none;
    background: #bada55;
    padding: 5px;
}
#cities {
    display: none;
    
    width: 340px;
    height: 40px;
    border: 1px solid #999;
    padding: 10px;
    margin-top: 20px;
}

#cities ul li {
    padding: 5px 10px;
    margin-right: 10px;
    border: 1px solid #BBB;
    float: left;
    cursor: pointer;
}

JavaScript

var button = document.getElementById('cities-button'),
    citiesBlock = document.getElementById('cities'),
    hidden = true;

button.addEventListener('click', function(e) {
    e.preventDefault();
    
    if(hidden) {
        citiesBlock.style.display = 'block';
    } else {
        citiesBlock.style.display = 'none';
    }
    
    hidden = !hidden;
}, false);