Repeating fields are not a good choice for LineItem data in a relational database such as FileMaker. You will have much more flexible control of your data if you import them into a related table with one record for each line item. And this can be done from your csv file. Whether you take that advice or not, we'd need to know how the lineitems are arranged in your CSV file. Is each lineitem in a different column or do you have multiple rows for one PO, with one lineitem to a row?