Separate work and private with one ID

With a single AppleID, you cannot separate content. An AppleID creates a single iCloud, FaceTime and iMessage account. Those single accounts do not allow for any separation of content.

You would need a second AppleID to create work-specific Apple service accounts if you wish to keep things separate. You can certainly have a second AppleID for use with iCloud, FaceTime and iMessage, but use one common AppleID in the App, iTunes and iBook stores to keep all your purchased content on one primary AppleID.