How to sales partner create sales order

i have 3 levels on sales, customers order to the distributor (sales partner) and distributor (sales partner) order to the brand principal,what i want to ask is how to distributors (sales partner) create the Sales Order because the sales order only displays end customer data.
please advice

please refer, hope this will help.

For the customer portal works for the sales partner you will need to ensure that all customers accessible by the sales partner have one contact with the same email for the sales partner.

Alternatively you can create an user for the sales partner, and associates his own sales partner record for his user, using the “User Permissions” it will set the field sales_partner as default for his sales partner record, and also will filters only his sales into the list