When you run get_post_meta( get_the_ID(), '_crosssell_ids',true);
you get an array of all the products that the current product cross sells to.
How do I reverse that? To get all the products that cross sells to the current item?
Example:
Not this: Product 1 -> Cross-sell: Product 2, Product 3
But this: Product 3 <- Cross-sell: Product 1