I've been trying to track this view down because I noticed it calls a partial view which seemed to behave as a TierPrices environment which I'm interested in. It did appear as it was related to ProductDetails view... And for future reference if you have any tip/trick to quickly preview a view without say having to drill down to it from the Controller and Route would appreciate.
ProductDetails.Grouped.cshtml or ProductTemplate.Grouped.cshtml? If it's ProductTemplate.Grouped.cshtml, then it will be invoked when you go to product details page of Grouped (product with variants) type product.