A handy Plugin that help you to set a post to child post of another…
Add Hierarchy (parent) To Post Wordpress Plugin - Rating, Reviews, Demo & Download
Plugin Description
You can add parents to posts (like pages). NOTE:!!!!!!!!!!!!!
** 1)** Only issue is that, VISUALLY you will see incorrect slug-link in POST-EDITOR page [however,the link is correct while clicking]. See the screenshot-1.
** 2)** I dont know how the plugin affects site performace. Maybe it could bebetter to avoid this plugin if you have high traffic website.
** 3)** Note, plugin wont delete anything. However, Use at your own risk and if permalinks will be broken, restore backup of ‘rewrite_rules’ option.
(P.S. Note! This is a NON-SLOWING Plugin. See other MUST-HAVE PLUGINS for everyone. )