This is easy default Prestashop module for creating filters (price, color, attributes and etc.).
To show the filter in the products category list you need to enable and configure the module. It will be shown only in the product categories pages (not in the cms pages, contacts, about us). It can be shown either for “All product categories” or for specific product categories (that you can choose).
Configuration path Back-office > Modules > Layered navigation block, configuration
If you've configured the module and it won't display, make the following steps:
If there's wrong price shown or wrong attributes, press “Rebuild entire price index” or “Build attribute index” accordingly.