Currently, when synching product from BC to Shopify, when there are nested variants (such as color and size), the variants are sent as they are in BC to Shopify (as a one-dimensional list of variants). In Shopify it is possible to create the nesting of the two variances (for example, first color, then size). However, to synch back this information to BC, the product synch direction needs to be reversed temporarily, and the mapping of the variants must be redone in BC by hand.

It would be ideal if variants could be rearranged directly in the product page in BC creating the right sets of variants (the table seems to support three levels).