macos – Unmerge Time Machine Backups of Different Machines

I have an external Hard Drive with a Time Machine partition, which contains backups of my current computer (a 2017 MBP).
This drive was also used as a Time Machine drive for a previous computer (a 2008 MBP) with the same computer name, but with a completely different file structure (the 2017 MBP was not restored from the 2008 MBP backup). I have not made backups from the 2008 MBP since I stopped using it regularly in 2017.

When I started backups from the 2017 MBP, I wasn’t proficient enough to check that the backups would be separated, and it looks like they haven’t been (I assume now that there is just a massive diff between the last backup of the 2008 MBP and the first backup of the 2017 MBP), since the computers were named the same thing.

I am now worried that as the hard drive fills up, I will start to lose backups of the 2008 MBP, rather than older backups of the 2017 MBP. Therefore, is there a way to ‘branch’ the pre-2017 backups to a new backupdb so that I have two separate backups, rather than what Time Machine believes to be a single chain?