Explanation/Reference:
Explanation:
One customer, who was looking for OU level filtering to import selected users from On-Premises active directory to Office365.
Configure OU level filtering for Office365 directory synchronization.
1. Logged in to your Domain controller
2. Created an OU (Organisational Unit) from your AD (Active Directory) a. In my case I named it "DirSync"
3. Move all those users you want to sync, to that DirSync OU.
4. From your DirSync Server navigate to <Drive>\Program Files\Microsoft Online Directory Sync
\SYNCBUS\Synchronization Service\UIShell
5. Double click on miisclient.exe
6. This opens a console something similar to the below screen capture

7. Identity Manager, click Management Agents, and then double-click SourceAD.
8. Click Configure Directory Partitions, and then click Containers, as shown in the below screen capture.

9. Click OK on the SourceAD Properties page.
10. Perform a full sync: on the Management Agent tab, right-click SourceAD, click Run, click Full Import Full Sync, and then click OK.
References: http://blogs.msdn.com/b/denotation/archive/2012/11/21/installing-and-configure-dirsync-with- ou-level-filtering-for-office365.aspx