Configure ML Extractor - Extractor's Internal Taxonomy not enough

Hi,

When configuring the ML Extractor for Invoice, I need to map 3 names: Vendor name, Sold To Name, and Ship To Name. But I cannot find enough name fields from the Extractor’s Internal Taxonomy, and the same field cannot be used twice. Also it cannot be saved when left blank.

What should be done in this situation ? I am using Community version.

Thanks.