CSS

<style>
#d3 {
    display: none;
}
</style>
HTML and JavaScript

<input id="button" type="button" value="Show more" onclick="showMore()">
<div id="d3">
    <input type="button" value="Show less" onclick="showLess()">
    <input type="button" value="Show less" onclick="showLess()">
    <input type="button" value="Show less" onclick="showLess()">
</div>
<script type="text/javascript">
var button = document.getElementById("button");
var d3 = document.getElementById("d3");

function showMore() {
    button.style.display="none";
    d3.style.display="block";
}

function showLess() {
    button.style.display="inline-block";
    d3.style.display="none";
}
</script>