A group ID needs to be assigned to all your products in a particular category to be able to identify which group the product belongs to. For e.g.: All the ladies sandals of all colours and sizes would have the same group ID.
A group ID needs to be assigned to all your products in a particular category to be able to identify which group the product belongs to. For e.g.: All the ladies sandals of all colours and sizes would have the same group ID.