JSFiddle - React, Tailwind, and code Playground

HTML

<div class="menu">
    <div class="navigation">icon Home</div>
    <div class="dropdown">
        <div class="items">icon Default</div>
        <div class="items">icon Reports</div>
        <div class="items">icon Other</div>
    </div>
    <div class="navigation">icon Home</div>
    <div class="dropdown">
        <div class="items">icon Default</div>
        <div class="items">icon Reports</div>
        <div class="items">icon Other</div>
    </div>
</div>

CSS

.menu {
    position: relative;
    background-color:silver;
    font-family:Arial;
    font-size:12px;
    height:25px;
}
body{
    background-color:green;
    height:300px;
    
}
.navigation {
    float:left;
    padding:5px 10px 5px 10px;
    cursor:pointer;
}

.navigation::selection { background:transparent; }
.navigation::-moz-selection { background:transparent; }

.navigation:hover {
    background-color:gray;
}

.navigation.active {
    border:1px solid black;
    border-bottom-color:white;
    padding:4px 9px;
    background-color: white;
    position:relative;
    z-index:1;
}

.dropdown {
    display:none;
    border:1px solid black;
    border-bottom-width:2px;
    background-color:white;
    position:absolute;
    top:24px;
    padding:5px 10px;
    cursor:pointer;
}

JavaScript

$('.dropdown').each(function() {
    $(this).css('left', $(this).prev().position().left);
});

$('.navigation').click(function(event) {
    $(this).siblings('.navigation.active').click();
    $(this).toggleClass('active').next().toggle();
    event.stopPropagation();
});
$(document).click(function(event) {
    $('.navigation.active').click();
    $('.navigation').removeClass("active");
});