Make Woocommerce Attribute value for Product Variation as multiselect drop-down

When creating a product variation (for a chosen variable product) in Woocommerce, it is possible to choose only 1 value for each attribute from a drop-down select. We need to change this behavior for one of those attributes. We need to be possible to select more than one value, aka to make the drop-down working as multiselect. This change should be reflected in proper execution of the values written for this field in the database, so any product filter for woocommerce doesn't break and it can proceed the new multiselect logic correctly - if necessary a loop of the field values to be proceeded, or etc. We need this custom coding done in a such a way that it can run smoothly on further woocommerce updates - added via functions, hooks, etc. instead of hacking directly the woocommerce code and thus making it difficult for future plugin updates.