Create filter for several categories

Hi,

I have several main categories as well as sub- and sub-sub-categories. For example:

<li>Clothing</li>
    <li>Pants</li>
	    <li>Jeans</li>
		<li>Trousers</li>
		<li>Cargos</li>
    <li>Tops</li>
	    <li>Sweaters</li>
		<li>Sleeveless</li>
		<li>Vests</li>
    <li>Dresses</li>
	    <li>Elegant</li>
		<li>Wedding</li>
		<li>Casual</li>

Now I need to have a category filter on “Pants”, “Tops” and “Dresses” that displays the child categories, so for example the filter on Pants should display Jeans, Ttrousers and Cargo whereas the filter on Tops should display Sweaters, Sleeveless and Vests etc. Do I need to create multiple filters for this or is there a general way to set up a filter to display child categories?

Also, I am having aa problem with the AJAX loading: for the quick second of loading, wile the spinner is also being displayed, the pagination quickly appears at the top of the page. I don’t hae any pagination enabled, since I am displaying all products on the pages without page 2, page 3 etc, but for some reason while the Ajax is loading the pagination numbers appear for a second at the top. How can I disable this?