I've done a bit of searching trying to find an up-to-date solution to this but I'm not so certain with Google support answers nor with previous threads here.We have multiple domains on a Google Apps for Business account and we want to move most of them ( not the primary one ) to their own separate Google Apps accounts (so they will be the primary domain respectively for each new account).What is the best option to do that without data loss?The entry for data migration in Google supports omits any mention to domain transfer and where that would take place in the process.The most comprehensive answer I found is from 2012 and I'm not sure if it still applies.
Transfer domain & data from one Google apps account to another
google apps;migrate data
This is a very complex process that should not be undertaken unless you absolutely have to. Based on my experience I recommend involving a consultant that has done this process several times before. You will need to perform all of the following steps:Migrate all data you want to keep from the old Google Apps accounts. Delete the domain from your existing Google Apps environment. Note the bottom section of this article on Reusing your domain. Wait up to 24 hours for this domain to be purged. Create a new Google Apps environment with the old domain name as the primary domain. Create all the accountsImport all the data from the first stepYou can't use the data migration directions you linked to because the domain can't exist in both the new and old Google Apps environment at the same time. This means you need to export all data and reimport it. Those directions are focused on having a source and target account that exist at the same time. 