Thank you for your reply, Lassoan. But is there a more detail instruction on how to import the lablemap volume? I clicked the Import button, but nothing happened. 
. In addition, it seems the Copy/move segments function will do the same job. (Link: Documentation/Nightly/Modules/Segmentations - Slicer Wiki). However, it doesn’t say how to select the node in the right square. Operation system: Win7. Version: 4.7.0. Thank you very much.