we have a couple of custom meta boxes for product (custom post type). one custom meta box key is area_required_width, and we have numbers input for it when publishing products, now we want to have a dropdown including <5, 5-10, 10-20, 20-50, >50 to search this key value of area_required_width at frontend for users.
I know that we can use custom WP_query to search if at backend we store ranges instead of input numbers as frontend. the thing is that our data stores is numbers we input while search criteria is different ranges like <5, 5-10 ...