JSFiddle - React, Tailwind, and code Playground
HTML
<input type="button" id="showMore" value="Show More">
<p class="mult_entries select">
<select class="filter">
<option value="dogs">dogs</option>
<option value="cats">cats</option>
<option value="chickens">chickens</option>
<option value="pigs">pigs</option>
</select>
</p>
<p class="mult_entries select">
<select class="filter">
<option value="dogs">dogs</option>
<option value="cats">cats</option>
<option value="chickens">chickens</option>
<option value="pigs">pigs</option>
</select>
</p>
<p class="mult_entries select">
<select class="filter">
<option value="dogs">dogs</option>
<option value="cats">cats</option>
<option value="chickens">chickens</option>
<option value="pigs">pigs</option>
</select>
</p>
<p class="mult_entries select">
<select class="filter">
<option value="dogs">dogs</option>
<option value="cats">cats</option>
<option value="chickens">chickens</option>
<option value="pigs">pigs</option>
</select>
</p>
JavaScript
$("p.mult_entries select:gt(0)").hide();
$("#showMore").click(function(){
$(".mult_entries select:hidden:first").fadeIn("slow");
});
$(".filter").change(function(){
var val = $(this).val();
$(".filter").not(this).children().each(function(){
if ($(this).val() == val) $(this).attr('disabled','disabled');
});
})