Importing layered Bip01 multiple meshes?

In the attached image you can see that there is a layer, called Bip01, which contains several meshes. However, when i import with various settings into Unreal, all these layers inside the Bip01 bone hierarchy are not there in Unreal. Is there maybe an easy fix for this? Do I need 3DSMAX? Is there an import trick in Unreal? Thanks.

Notice the model has not been altered with Blender - comes from Character Studio, just using Blender to show the missing bones.

To make this work you can either export layered meshes separately, and then attach them later, or add a “locator” bone with Maya, move the entire rig into the locator, then export. This way Unreal finds the root meshes. However, when i move all into the Locator, other layered meshes break in my example rig, and i have to export those and reattach them later…