You can upload local AutoCAD or Civil 3D folders to the Files tool using the Bulk Upload Tool and preserve the folder structure as well as maintain reference relationships in the project.
This is achieved by using the DWG Migration and Integrity for Docs tool to export a JSON file containing the file and folder information. This JSON file is imported to the Bulk Upload Tool and defines:
This enables the Bulk Upload Tool to upload files in the correct order and ensure project integrity.
You now need to follow the following links, starting with Install DWG Migration and Integrity and Desktop Connector Tools.