The default plug-ins to the focus management system may not handle this case but they are just defaults and you have the ability to plug in your own navigation that is as complicated as you like.
There is another thread about this. [RFC] BigBanana: mouseless navigation - #25 by Pesegato
…where I’ve discussed a different-but-similar situation with another user. Essentially, you can hook in and define on your own what focus traversal points to what and when… just by implementing some interfaces in some controls on your spatials/buttons/etc.