Show parent child relationship of taxonomy term in view
You can also try Views tree module.

Project page says


  This module provides a tree-based style plugin for Views. It is
  equivalent to the tree-based style template from Views 1.
  
  It is based off of the list style. Although it generates a nested
  view, there is still only a single query run for the view making it
  quite performant.
  
  Compatibility
  
  This module has been tested and used with the following
  relationship-oriented modules:
  
  Taxonomy (in core) - parent/child relationships