For search only for a category on store you must change the page
/catalog/controller/product/product.php
line 199:
search for:
Code: Select all
if (isset($this->request->get['search']) || isset($this->request->get['tag']))Code: Select all
if (isset($this->request->get['search']) || isset($this->request->get['tag']) || isset($this->request->get['category_id']) || isset($this->request->get['sub_category']))
