Product Groups that track multiple individual products in inventory

My issue is about using internal inventory tracking.

I have 15 individual products each with thier own SKU ... so far, so good.

The challenge is I have additional SKUs that are product 'groups' ... or a single SKU that contains more than one individual product (i.e. Combos, Kits, & Wholesale cases) ... So when I 'sell' a Kit, Combo, or wholesale case, I want inventory to track multiple different products or multiple units of a single product when each of those Kits, Combos, or Wholesale cases are sold.

It's obviously a 'logic' challenge ...  if a product group SKU is sold, then subtract x number of these multiple items. I'm confident I could properly set if up IF ShipStation had the proper methods to accommodate that purpose. It's an 'automation' or logic setup.

I was advised to see if my store (e.g. BigCommerce) can send the individual products to accomplish the same end result.

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