The document provides a guide on understanding segment reporting in SAP according to IFRS 8, highlighting the definition of operating segments, criteria for determining reportable segments based on revenue, profit, and asset thresholds. It explains the role of the Chief Operating Decision Maker (CODM) and discusses how to structure profit and loss reporting and balance sheets at the operating segment level using SAP's new GL functionality. Additionally, it outlines the necessity for segments to meet specific quantitative thresholds to be reported and how to ensure that reportable segments comprise at least 75% of total external revenue.