What is a requirement for restoring individual files from an NDMP backup with the backup/archive...

According to IBM documentation1, one of the requirements for restoring individual files from an NDMP backup with the backup/archive client GUI is that a Table of Contents (TOC) must be created during the backup. The TOC contains file-level restore information that is used by thebackup/archive client GUI to display and select files for restore. The TOC is stored in a different storage pool from the one where the backup image is stored.

https://www.ibm.com/docs/en/spectrum-protect/8.1.11?topic=servers-file-level-backup-restore-ndmp-operations