JSFiddle - React, Tailwind, and code Playground
HTML
<select class="dropdown">
<option value="one">One</option>
<option value="two">Two</option>
<option value="three">Three</option>
</select>
JavaScript
var data = {
one: ['Four', 'Five', 'Six'],
two: ['Seven', 'Eight', 'Nine'],
three: ['Ten', 'Eleven', 'Twelve']
}
$('.dropdown').change(function () {
$('.dropdown2').remove();
var newSel = $(this).after('<select class="dropdown2" />');
var option = $('.dropdown').find(":selected").text();
data[option.toLowerCase()].forEach(function(opt){$('.dropdown2').append('<option>' + opt + '</option>')});
})