JSFiddle - React, Tailwind, and code Playground

HTML

<label for="first">Prva List</label>
<select id="first">
    <option value="">Select one</option>
    <option value="Germany">Germany</option>
    <option value="Australia">Australia</option>
</select>
<hr>
<label for="second">Druga List</label>
<select id="second">
    <option value="">Select one</option>
    <option value="Serbia">Serbia</option>
    <option value="Andorra">Andorra</option>
</select>

JavaScript

$('#second').change(function () {
    var val = $(this).val();
    if (val == 'Andorra') {
        $('#first').val('');
    }
});