JSFiddle - React, Tailwind, and code Playground

HTML

label1: <span id="label1">-</span><br />
label2: <span id="label2">-</span><br />
<select id="Address_CountryId" name="Address.CountryId">
<option value="">Select</option>
<option value="226">Afghanistan</option>
<option value="3">Albania</option>
<option value="4">Algeria</option>
<option value="5">Andorra</option>
<option value="6">Angola</option>
<option value="10">Antigua and Barbuda</option>
<option value="7">Argentina</option>
<option value="8">Aruba</option>
<option selected="selected" value="227">Australia</option>
<option value="11">Austria</option>
<option value="240">Azerbaijan</option>
<option value="12">Azores</option>
<option value="230">Bahamas</option>
<option value="18">Bahrain</option>
<option value="24">Bangladesh</option>
<option value="219">Barbados</option>
<option value="15">Belgium</option>
<option value="22">Belize</option>
<option value="16">Benin</option>
<option value="17">Bermuda</option>
<option value="19">Bhutan</option>
<option value="25">Bolivia</option>
<option value="26">Botswana</option>
<option value="27">Brazil</option>
<option value="202">British Virgin Islnd</option>
<option value="28">Brunei Darussalam</option>
<option value="29">Bulgaria</option>
<option value="21">Burkina Faso</option>
<option value="30">Burma</option>
<option value="23">Burundi</option>
<option value="31">Cameroon</option>
<option value="32">Canada</option>
<option value="42">Canal Zone</option>
<option value="41">Canary Islands</option>
<option value="46">Cape Verde</option>
<option value="49">Cayman Islands</option>
<option value="33">Central African Rep</option>
<option value="36">Chad</option>
<option value="35">Channel Islands</option>
<option value="37">Chile</option>
<option value="43">Colombia</option>
<option value="40">Comoros</option>
<option value="171">Confed of Senegambia</option>
<option value="44">Congo</option>
<option value="39">Cook Islands</option>
<option value="45">Costa Rica</option>
<option value="232">Croatia</option>
<option...

JavaScript

function updateAlternativeDropdown() {
    var dropdown = document.getElementById("Address_CountryId"),
        splittedValues = dropdown.options[dropdown.selectedIndex].value.split('_');
    document.getElementById("label1").innerHTML = splittedValues[0];
    document.getElementById("label2").innerHTML = splittedValues[1];
}

$('#alternativeNumbers').change(updateAlternativeDropdown);