Hi,
1/ About filters
Can you please provide us some details about your filter configuration.
It looks like the filter is not processed at all.
And if you want to display more products from more categories, you can just change the "category" in the product listing menu/module.
1/ About the Joomla search plugin (even if you are not using it)
The search plugin look for product in categories with the category_type "product".
There is not root configured in the plugin for the search.
So you have to be sure that your outside categories right have this category_type set (and also, are published).
(Note: for batch processing, the mass action are still quite useful )
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.