The following steps will help you move your OneNote file from one tenant (the source) to another tenant (the target):
1.Log into your Office 365 account in your source tenant.
2.Open your One Drive for Business 0365 application online were your OneNote .one files, that are needed to be moved, are saved.
3.Open the .one file you plan on moving from this source to your target tenant, be sure to open the file in the full desktop OneNote application - you can do this by clicking "Edit In OneNote"
4.In deskotp OneNote, select File, then Export. Select Notebook under "Export Current". Select OneNote Package (*.onepkg) under "Select Format". Lastly, Click Export.
5.After selecting Export, choose whether to export to either your desktop or a folder on the desktop. Whichever you choose, pick an easily accessible location.
6.DONT SKIP THIS STEP
Log In to your new One Drive for Business account, your target tenant, open any OneNote file form your new One Drive for Business location. Select the "Edit in OneNote" option, which will open the file in the full OneNote desktop application. This creates a link between your One Drive for B?usiness and the One Note desktop application. Leave the notebook open and follow the remaining steps as mentioned.
7.Upload the .onpkg file saved in step 5, to the new (target) One Drive for Business. After you have uploaded the .onepkg select it to open it. It will automatically open or download and open to your full One Note desktop application by default. You want this to happen but dont unpack the file yet.
8.After the .onepkg is opened by you in One Drive for Business in the OneNote Desktop application you must first change the path before clicking the create button.
9.You dont want to unpack the Notebook to a local location. Instead, click the drop down for the path, change the location to what looks like a web URL that looks similar to the following: https://tenant-my.sharepoint.com/personal/youro365username_domain_com/Documents/. Click Create.
NOTE: this URL option will not appear if you did not complete step 6.
10. The Notebook will now unpack the .onpkg into a .one file, as it was in your original source One Drive for Business location. And it may take a minute or two to unpack the file. You should now have 1 single .one file with the same name located in you target One Drive for Business exactly as it appeared in your source One Drive For Business. It should be a folder with a bunch of separate .one files that use to be the different sections of the original OneNote document.