How to report postprocessing lead time at the item/org level

Summary: Trying to report the postprocessing lead time at the item/org level in OTBI

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Trying to report the postprocessing lead time at the item/org level in OTBI using Procurement - Procure To Pay Real Time or Procurement - Purchasing Real Time subject areas however when I add any purchase order detail to the report I only get the postprocessing lead time at the item master level. Without any PO level data and only item level data I can report on the postprocessing lead time at the item/org level. Have tried several calculated field options but have been unsuccessful in my efforts. Wondering if this is even possible or if it is