How can I backup 2 external hard drives to 2 different external hard drives with time machine for both?

The question explains itself. Currently I have my 12tb hard drive backed up to another 12tb hard drive through time machine. I just bought 2 more 12tb hard drives because I ran out of space, and I now want to do the same thing with them. I run the type of video business where every job I've ever done needs to have easy access to editing because lots of our work is with ongoing clients. That's why simply having an archive won't do. Each of the 2 main 12tb hard drives will need to be accessed regularly and will also need to have regular time machine backups to each ones backup drive. How can I do this?