Exchange 2013 debuted last year with the ability to configure a Hierarchical Address Book (HAB) for on premises deployments.
The hierarchical address book (HAB) is a feature in Microsoft Exchange Server 2013 and Microsoft Outlook that enables end users to browse for recipients in their Exchange organization using an organizational hierarchy. In most Exchange 2013 deployments, users are limited to the default global address list (GAL) and its associated recipient properties. Additionally, the structure of the GAL often doesn't accurately reflect the management or seniority relationships among recipients in your organization. Being able to customize an HAB that maps to your organization's unique business structure provides your users with an efficient method for locating internal recipients.
Now, a tenant administrator for Office 365 is able to configure a HAB using the same commands one would in an on premises deployment.
For more information on how to configure and use a HAB, please refer to Hierarchical Address Books: Exchange 2013 Help?.