2018-06-27, 19:33:09
Why don't you make the parents visible and just exclude them from the menu so that no direct link to the parents is shown? If these should also not be accessible, you can simply redirect:
RewriteRule ^category-1/$ category-1/child-of-category-1/ [R=301,L]
RewriteRule ^category-1/$ category-1/child-of-category-1/ [R=301,L]