By default when searching the Active Directory, you can find an object easily but the heirarchy is not shown. You can very easily enable this so that you can locate objects and see in which Organization Unit (OU) they exist.
With the Active Directory snap-in for the Microsoft Management Console open, go to View and click on Advanced Features so that there is a check mark to the left of it.
Now when you do a search double-click (or right-click, Properties) on the search result you want to investigate.
A new window will appear. This is the standard window that you would have gotten without enabling the Advanced Features except that now there is a tab called Objects. Click on this and it will show the hierarchy where you can find the object in your AD.
Now you can see the the libnonadmin object is located in the uc.eduLibraryTesting OU.