Only show product or categorie as a filter result

Hi,

That's possible. First you need to deactivate the filters on your products listing menu/module so that it displays your categories menu item with the products like you want (the default "categories listing" menu item of HikaShop should already do that).
Then, setup a products listing menu item displaying all your products via the Joomla menu manager (the default "products listing" menu item of HikaShop should already do that).
Then, configure the HikaShop filters module with the id of the menu item you created in the "Menu" option of the module with the "force redirect" option turned on.
That way, when the user uses the filters module, he will see the matching products throughout all your categories while otherwise, he will be able to navigate your products catalog by categories.

There is no option to that.
You could try to add the code:

global $Itemid;
if($Itemid!=XXX) $datas=array();

$html[$key]=$this->filterClass->displayFilter($filter, $this->params->get('main_div_name'), $this, $datas);