Move Multiple Thoughts en Masse from One Parent to Another
If necessary, create the new thought that will serve as the parent for the thoughts you want to move
Using CTRL-Click, select all the child thoughts you want to move
Make the new parent thought active > Right click in the selection box to "Link selected thoughts as children"
Keeping the selection box open, navigate back to the original parent (parents) of the moved thoughts > Right click in the selection box to "Unlink Selection"