Separate animation export into multiple objects

When it comes to first person viewmodel animations, it's pretty common to animate the arms and weapon together, and then export them separately, so that they have their own animations and can each have their own animation controller. This allows for weapon variations to be animated differently while keeping the arms the same. (eg. Locking the slide back on a pistol without having to double every arm animation for this variation)

So in short, it would be nice if we could export just a section of the hierarchy, with the selected object being the root of this new animation. Then we would be able to create an animation controller on just this object. Likewise I guess this would also need the ability to ignore certain objects in a hierarchy when exporting so that there are no conflicts.