Listing search form doesn't show subcategories

The listing search form only displays the categories and doesn’t show the subcategories. i want it to show both subcategories and keywords. and also bring out anything related to the item the user searches for on the search form. for example if a user searches for Table and its not a listing category or subcategory but it’s a keyword in a title or header to a listing i want it to come up

Hi,

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