I think this will solve you problem with slight change in html
HTML
<ul>
<li><span>1</span>
<ul>
<li><span>1</span></li>
<li><span>1</span></li>
<li><span>1</span>
<ul>
<li><span>1</span></li>
<li><span>1</span></li>
<li><span>1</span></li>
<li><span>1</span></li>
<li><span>1</span></li>
</ul>
</li>
<li><span>1</span></li>
<li><span>1</span></li>
</ul>
</li>
<li><span>1</span></li>
<li><span>1</span></li>
<li><span>1</span></li>
<li><span>1</span></li>
</ul>
CSS
ul {
list-style: none;
}
ul li span{
display:block;
}
ul li:hover > span {
background-color: pink;
}
ul li:hover ul li {
background-color: transparent;
}
Example : https://jsfiddle.net/yvt8xecz/3/
With added span you don't need to fight with ul li structure just change the color of span