We can assign a parent customer to a group of customers. This can be done by specifying the parent customer in the customer record.
All the transactions of the sub-customers will be available in the parent record.
In order to set multiple sub-customers to a single parent we can use CSV import.
In the import file we need to specify the internal id of the sub-customer and the parent company to which it should be related to.

In order to add a single new sub-customer to a parent customer we can navigate to list->relationship->Customers. Then add the sub-customer by clicking the add sub-customer button

Or we can specify the parent company in the customer record to specify to which parent it should belong to.
Adding a sub customer to a parent record.
