From time to time, you may have products that are sub-categorized products. Meaning, you might have different sku's for a tee-shirt that comes in three different variants. If the products are basically the same (save for cosmetic variance like color, etc) you may want to aggregate reviews collected for the individual product up to the parent level product.
Using product hierarchies make collecting reviews for parent level products faster
You can aggregate the reviews for the sub-products, up to the parent product
Some examples of this include
I sell a type of brand of home paint, in different colors
I sell the same tee-shirt cut with five different color variants
Instead of having each product collect reviews individually, the aggregate review is combined for all the products.
Connecting Products together to share reviews
You can provide some optional data to associate products to parent level SKU's and have them share reviews. You can learn more about where to place the code here under Feed Ingestion.
parent_id: "PARENT_LEVEL_ID", - this can be whatever number you deem necessary. So whatever product shares this parent level ID, will share the same reviews.
parent_name: "PARENT_NAME", - the parent name of the top level product as it shows in the ResellerRatings portal or the
parent_image: "PARENT_IMG_URL", * optional