WooCommerce

When WooCommerce is active, product records get three extra attributes automatically:

Attribute	Use it for
price	Sorting and filtering by price
stock_status	Filtering to in-stock products
on_sale	A "sale items only" toggle

Use them in a View like any other attribute, for example with a Toggle Refinement for on_sale.

SearchSync also makes each visitor's purchased products (from their 500 most recent paid orders) available to the search page, for developers building "buy again" style views. There are no WooCommerce-specific filters in the editor yet.