I have a product field which is by default in the woocommerce and i have added another field custom field (ACF) which is stock_number on my product/shop page i can search for products by title only i want to include the custom field stock_number data in the search as well e.g. so if some one search for something which is in custom field the result should apear the below example will explain it bit more.

Title   Stock_number
 A          B
 C          D

currently what woocommerce does is if i search for A or C it will show the result but if i search for B or D it will not show the result so i want to make the stock_number field searchable