Additional Meshes can't activate bones in Master Skeleton

I have a problem with playing animation.
How it can work in an animation blueprint:

  1. I have a Skeleton in which there are two separate hierarchies (part1 and part2, tied to the common root bone).
  2. I select an skeletal mesh asset as a preview mesh, which is skinned only to part1.
  3. I turn on display all the bones, I see the only bones from part1.
  4. As an additional geometry, I choose a mesh that is skinned only to part2.
  5. I play an animation that contains the keys for part1 bones. The bones of part1 are moving correctly.
  6. I play an animation that contains the keys for part2 bones. Bones from Part 2 are not animated (do not exist).

If you replace Preview Mesh asset which is skinned to part 2, everything will be reversed.

The same happens and runtime.

So, I guess that skeletal meshes witch reference to master pose to drive themselves can’t affect which bones are active.
Is it possible to provide data about active bones from additional meshes to the Master Skeleton? Using bluepints, if it possible.