How can I restrict users to some parents node with node hierarchy?
I suggest you attach a taxonomy vocabulary to your content type and use the Taxonomy Access module.

So, create your vocabulary:


Arts &amp; Science
Economy
News


Create roles based on taxonomy:


arts_role
economy_role
news_role


Assign permissions to roles:


Edit terms in Arts &amp; Science to arts_role
Delete terms from Arts &amp; Science to arts_role
Edit terms in Economy to economy_role
Delete terms from Economy to economy_role
Edit terms in News to news_role
Delete terms from News to news_role


Assign your users to your roles:


Stephanie gets arts_role
John gets economy_role