Option to mirror switching tabs in different groups.

I'm having a hard time searching for other references to this because I don't know what to call it. So, apologies if it's already here or even already implemented and I can't find it...

Here's the idea/use case:

I like to split with two groups "Columns: 2", and put implementation files on the left and test files on the right. In order to see an implementation file and the corresponding test file at once I have to either click on them both or do some tricky key combos (switch tab with ctrl-tab or command-ctrl-arrow, then ctrl-2, and switch tab again). I'd like to be able to switch tabs and have both my corresponding implementation and test switch at the same time.

I'm not sure what the best way to implement this is. Any ideas?