JSFiddle - React, Tailwind, and code Playground
HTML
<select id="menlist" name="menlist">
<option value="1">Sausis</option>
<option value="2">Vasaris</option>
<option value="3">Kovas</option>
<option value="4">Balandis</option>
<option value="aa">Name aa</option>
<option value="bb">Name bb</option>
</select>
<select id="menlist2" name="menlist2">
<option value="1">Sausis</option>
<option value="2">Vasaris</option>
<option value="3">Kovas</option>
<option value="4">Balandis</option>
<option value="aa">Name aa</option>
<option value="bb">Name bb</option>
</select>
JavaScript
$(function(){
$("#menlist").keyup(function(){
var value=$(this).val();
$("#menlist2 option[selected]").attr("selected", "selected");
});
$("#menlist").change(function(){
$("#menlist2").val($(this).val());
});
});