Setting up Previous Versions (Shadow Copies) in Windows Server 2012 is the same as setting up Previous Versions in any other version of Windows Server.
To setup Previous Versions, right click the drive that you want to setup Previous Versions on and click Properties. Click the Shadow Copies tab and select the drive you want to setup Previous Versions on, then click Enable.
You will then be prompted with a message asking you if you want to enable Shadow Copies; Click Yes. Next Click on Settings and setup a size limit (if required) and a schedule for Shadow Copies to occur on. You can leave these on defaults if you prefer. Click OK, then OK again and Previous Versions will now be setup on Windows Server 2012