the error message suggests that you are unable to copy a file or folder in Google Drive due to exceeding the shared drive hierarchy depth limit. Google Drive’s shared drive feature allows users to organize files and folders in a nested structure within shared drives.
“The limit of Google Drive of subfolder structure is 15.”A folder in a shared drive can have up to 20 levels of nested folders. We recommend that you avoid creating many folders in one shared drive. Members might have difficulty organizing and finding content. Instead, organize content into multiple shared drives.” – Shared Drive limits in Google Drive (Section: Folder nesting and moving)