You can upload any file to a shared folder or group like you do in a personal folder.
- Select the folder from the folder tree on the left and press the blue 'Upload' button.
- In the resulting window, select and confirm your desired file(s) to begin the uploading process
Note: privacy restrictions on these folders may prevent you from uploading files to them. In case you're not able to upload any file to a shared folder or group, you must contact their respective administrators and request the appropriate rights to be provided to you.