JSFiddle - React, Tailwind, and code Playground
HTML
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/css/select2.min.css">
<script src="https://code.jquery.com/jquery-2.2.4.min.js" integrity="sha256-BbhdlvQf/xTY9gja0Dq3HiwQF8LaCRTXxZKRutelT44=" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/js/select2.min.js"></script>
<select name="country[]" multiple="" data-placeholder="Select country" class="form-control chzn-select" required="required" id="country">
<option disabled="disabled" value="1">Abu Dhabi</option>
<option value="2">Dubai</option>
<option disabled="disabled" value="3">Singapore</option>
<option disabled="disabled" value="4">Thailand</option>
<option value="8">Afghanistan</option>
<option value="All">All</option>
</select>
JavaScript
$(".chzn-select").select2({selectOnClose: true}).on("select2:selecting", function(evt) {
if(evt.params.args.data.id == 'All') {
} else {
}
});