JSFiddle - React, Tailwind, and code Playground
HTML
<script src="https://code.jquery.com/jquery-2.2.4.min.js"></script>
<select id='s1'>
<option>Selecione</option>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
<select id='s2'>
<option>Selecione</option>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
JavaScript
$("select").change(function() {
var id= $(this).attr('id');
var valor=$(this).val();
var selects = $('select').not('#' + id).find('option[value="' + valor + '"]:selected');
if (selects.length > 0) {
console.log('achei');
}
});