Added. You can now split the page by labels by any field. To use you must check in Separate Pages on Selected Fields (3). And select the field name you want to split on by the top (4).
To use for classes you would need to make sure you are creating labels for children(1) and that you have one period selected (2). Then when you check in Separate Page on Selected Fields (3) it will auto select the class files by the top right (4).