JSFiddle - React, Tailwind, and code Playground
HTML
<section id="citys">
<div class="container">
<div class="row">
<div class="col-md-3">
<form>
<div class="form-group">
<label for="sel1">Cidade</label>
<select class="form-control" name="list_citys">
<option value="all_city">Todas</option>
<option value="city_sp">São Paulo</option>
<option value="city_barueri">Barueri (Tamboré)</option>
<option value="city_campinas">Campinas</option>
<option value="city_guaruja">Guarujá</option>
<option value="city_santos">Santos</option>
<option value="city_santo_andre">Santo Andre</option>
<option value="city_sao_campo">São Bernado do Campo</option>
<option value="city_sao_jose_campos">São José dos Campos</option>
<option value="city_ribeirao_preto">Ribeirão Preto</option>
<option value="city_outlet">Outlet</option>
</select>
<br>
</div>
</form>
</div>
</div>
</div>
</section>
<section class="list_citys_shop">
<div class="container">
<div class="col-md-3">
<ul class="list-citys list-unstyled" data-category="city_sp">
<li>
<h4 class="shop-text-h4">São Paulo - Centro</h4></li>
<li class="new-citys">Second item</li>
<li class="new-citys">Third item</li>
</ul>
</div>
<div class="col-md-3">
<ul class="list-citys list-unstyled" data-category="city_sp">
<li>
<h4 class="shop-text-h4">São Paulo - Morumbi</h4></li>
<li class="new-citys">Second...
JavaScript
$('select[name="list_citys"]').change(filterList);
function filterList(e) {
var value = e.target.value;
if (value == "all_city") $(".list_citys_shop .new-citys").slideDown();
else $(".list_citys_shop .new-citys").slideUp();
$(".list_citys_shop ul[data-category*=" + value + "] .new-citys").stop().slideDown();
}