Can a document library or the subfolder be a reference in Copilot Notebook?

Yes. Copilot Notebooks currently supports adding SharePoint sites, document libraries, and folders as references.

The supported ways to add them are through Add references using Search or Link:

1. Open the notebook in the Microsoft Copilot app or OneNote.
2. Open Add references.
3. Add the SharePoint content by either:
   • Search: search for a SharePoint site, document library, or folder and select it.
   • Link: paste a URL.

When a SharePoint site, library, or folder is added, Copilot can use supported files in that location that the user has permission to access.

There are also important limits that explain why results may differ:

• Copilot only uses content from the sites, folders, or files added as references and only if access permissions allow it.
• For shared locations such as a SharePoint folder or site, Copilot considers the files available in that location and selects up to 300 relevant files for grounding.
• To guarantee a specific file is included, add that file directly to the notebook.
• Supported entity types include SharePoint sites and pages, folders. Another support article also explicitly states that document libraries can be searched and added.

Based on the documented behavior, this is not a documented limitation of Copilot Notebooks. Document libraries and folders are supported reference types. If a library or folder link does not return results while the full site or an individual file does, the documented guidance only confirms support and permission-based grounding behavior; it does not document a known limitation specific to library or folder references.

• Add references to your Microsoft Copilot Notebook | Microsoft Support
• How Microsoft Copilot Notebooks works | Microsoft Support
• Get answers and insights about your Microsoft Copilot Notebook | Microsoft Support