Creation of sub account and parent account

I want to create one parent account and multiple sub account under it.

So that I can relate single sub account to collect leads/ contacts from “abc” site and another sub account to collect leads/contacts from “Xyz” site.
so the single account can have only its leads/contacts listed in crm. It can’t access leads/contacts of “xyz”.
and also parent account can access all record.

Could you please provide proper detail how we can achieve this using suitecrm ?
Kindly provide your response as soon as possible as this is a basic need of our organization.