Drag child inline-blocks to other parent inline-blocks

I’d like to be able to drag a child block to become a child of another parent block.

For example, I have this block hierchy

Block 1

  • Sub-block A
  • Sub-block B

Block 2

  • Sub-block C
  • Sub-block D

After dragging sub-block B into Block 2, the new hierarchy becomes…

Block 1

  • Sub-block A

Block 2

  • Sub-block B
  • Sub-block C
  • Sub-block D

Issue created here