faceted_search_enabled definition

[tarponjargon]

these variables are referenced across the cornerstone codebase:

category.faceted_search_enabled
brand.faceted_search_enabled
product.faceted_search_enabled
product_results.faceted_search_enabled

but are not defined anywhere in the codebase itself. Can you point me to where these settings are configured? I tried bigcommerce chat and they said it's out of scope for them