A Sales Order has a one-to-many relationship with Items. It is like a sublist, or a list of lines within a record.
HOW TO MAP LINE ITEMS
You can access line items using the sublist name. In import mapping, each sublist is populated in the format Sublist Name : Field Name, such as Items : Department.
Select the line item to map the source data to this field:
PRO TIP: You can use line-level lookups as well to find data related to that specific line.
