You can restore an entire mailbox to the location that it was backed up from.
From the navigation pane, go to Protect > Applications > Office 365.
The Office 365 apps page appears.
In the Name column, click the app that contains the mailbox that you want to restore.
The app page appears.
On the Mailboxes tab, select the mailbox that you want to restore, click Restore, and then click Restore mailbox.
The Restore options dialog box appears, with options for restoring to the original location already selected.
For When message exists, specify what to do with existing items:
To overwrite existing items, select Overwrite unconditionally.
To not overwrite existing items, select Skip.