Here is a video tutorial on how to create a product rule. For more background, please read the below article.
Product Rules are used to tell the system which SKU(s)/quantity to add whenever the rule recognizes the bundle SKU ID.
On this page, you can manage any product rules you have set up. In the top right, you have the options to Group Inventory, Import Rules from another platform, or Create Rules. To start, create a new rule by selecting the Create Rule button:
In the popup window, select if the Rule is for a Group, Exclusion, or DropShip. Enter the SKUs associated with this new rule, and the title of the rule, and then select Create Rule:
To import rules from another platform, select the Import button. This will bring up a popup where you can upload a file with your rules - for more information on the formatting, select the Import Rules button at the bottom: