Organizational unit-based search in Google Vault

Vault users can now search for data within a specific organizational unit (OU), in addition to searching the entire domain or searching by user account. Searching within an OU reduces the number of irrelevant search results that a domain-wide search can produce, and eliminates the need to specify individual accounts. When performing a search within a matter, select Organization then select the OU you want to search. Accounts cannot be included in an OU-based search, but you can still optionally specify a date range and search terms.

For more information:
https://support.google.com/vault/answer/2462480

Editions included:
Google Apps for Business, Education and Government