This option is available in the premium version of the plugin.
Changing query operators may produce misleading results in combination with other plugin options. Please test the work of your filters to make sure that they work as expected after changing the query operators for your product taxonomies!
With the help of this option you can change the query inner-logics for each filter taxonomy from the default IN to AND, or NOT IN.
The default IN taxonomy logics filters the Woocommerce store for all the products that are associated with the selected taxonomy terms. Taking an online grocery store as an example, setting the IN relationship between the terms of its Product Categories will result in the display of all the products that belong to the selected categories. This means that if you filter such a shop for the Fruit, Berries, and Vegetables product categories, you will be shown all the products that are Fruit, Berries, or Vegetables.
The AND operator used in a relationship between the members of the same taxonomy will result in the display of the products that belong to ALL of the selected taxonomy terms at the same time. For example, tomatoes can be put both into the Vegetables, and the Berries product categories. If you now set the AND relationship for the members of the Product Categories taxonomy, and then filter for Berries and Vegetables, you will get the tomatoes displayed, along with any other products that are also associated with both of these categories. In a Colors filter with an AND operator, selecting Red and Yellow will display only the products that have both of those colors associated with them.
As you might have already guessed, the NOT IN logics filters the products for those that are NOT associated with the selected filter term. Returning to the grocery store example, in a case like that selecting Dairy products will show all the products that are NOT in the Dairy category. Clicking on the Fruit will remove fruit from the filtered result as well, and so on.