It seems like there may be some confusion in your question, however, I have created a CSS-only menu that functions similarly to the one on the site you referenced. You can view it here.
Below is the HTML code:
<ul class="main">
<li>all
<ul class="sub">
<li>books
<ul class="sub2">
<li>fiction</li>
<li>biography</li>
</ul>
</li>
<li>mobile
<ul class="sub2">
<li>android</li>
<li>cmda</li>
<li>battery</li>
</ul>
</li>
</ul>
</li>
</ul>
And here is the corresponding CSS:
li {
border:1px solid;
padding:1px;
}
.main {
list-style:none;
position:relative;
}
.sub, .sub2 {
list-style:none;
position:absolute;
display:none;
width:75px;
}
.sub2 {
float:left;
left:75px;
top:0px;
}
.main li:hover .sub,
.sub li:hover .sub2{
display:block;
}