https://knowledge.broadcom.com/external/article/102076/cbsuse-no-and-keyusage-atrribute.html
CBSUSE NO and KEY-USAGE atrribute
keyusage
https://userapps.support.sap.com/sap/support/knowledge/en/1664153
1664153 - Value of column "Parent atrribute" is displayed as null | SAP Knowledge Base Article
Use Hierarchy_Flattening and Flattening type is vertical, column of [Parent attribute list] become null when leaf flag is set to 1.