<ul class="list-unstyled">
    <li class="init">Выберите язык</li>
    <li data-value="value 1">RU</li>
    <li data-value="value 2">EN</li>
    <li data-value="value 3">CH</li>
</ul>
body{
  padding:30px;
}
ul { 
    height: 30px;
    width: 150px;
    border: 1px #000 solid;
    list-style: none;
}
ul li { padding: 5px 10px; z-index: 2; }
ul li:not(.init) { float: left; width: 130px; display: none; background: #ddd; }
ul li:not(.init):hover, ul li.selected:not(.init) { background: #09f; }
li.init { cursor: pointer; }

a#submit { z-index: 1; }
$("ul").on("click", ".init", function() {
    $(this).closest("ul").children('li:not(.init)').toggle();
});

var allOptions = $("ul").children('li:not(.init)');
$("ul").on("click", "li:not(.init)", function() {
    allOptions.removeClass('selected');
    $(this).addClass('selected');
    $("ul").children('.init').html($(this).html());
    allOptions.toggle();
});

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.min.js