Click on Theme preview on the themes listing page.

What links do you want to test?

1. I suggest that make a copy of your website and move it to your local computer for testing. That is where you can change the main theme at any time and later apply changes to the live website.

2. Modify the code of method cpt_category_tree in file published/SC/html/scripts/modules/test/class.test.php as shown below:

function cpt_category_tree($call_settings = null){
    $Register = &Register::getInstance();
    $smarty = &$Register->get(VAR_SMARTY);
    /*@var $smarty Smarty*/

    if(!is_array($smarty->get_template_vars('categories_tree'))){
        $this->methodCategoryTree();
    }

    $local_settings = isset($call_settings['local_settings'])? $call_settings['local_settings']:array();
    $smarty->assign ('extra', isset ($local_settings['tree'])? ($local_settings['tree'] == 'extra') : false);

    print $smarty->fetch('category_tree.html');
}

Then add the following snippet to the desired template where you want to display an extra category tree:

{cpt_category_tree tree='extra'}

and add the following conidition to file published/SC/html/scripts/templates/frontend/category_tree.html:

{if $extra}
extra category tree here
{else}
main category tree here
{/if}

You will have to write your own Smarty code in published/SC/html/scripts/templates/frontend/category_tree.html to determine what categories need to be included in either tree.