FocusManager: option to use next() with not only siblings

[ItsAsbreuk]

I have a form some elements.
I want to use focusmanager on all elements with the class '.focusable'

However, the elements are not just sblings inside a containernode. Some go 'deeper' because I placed them inside a div-element.

Th current focusManager skipped these items. It would be useful if you could make an option that makes all elements part of the 'next(), previous(), last() and first()'-methods.