Content hierarchy

How can create a content hierarchy like this?

Campaign
|
Lead
|
Opportunity
|
Account

When i click Campaign1 all the leads under Campaign1, all the opportunity nodes under Lead1, all the Accounts under Opportunity1 should shown like this

Campaign1
Campaign description

Leads:
Lead1 (link)
Lead2 (link)
..

Opportunities
Opportunity1 (link)
Opportunity1 (link)
....

Accounts:
Account1 (link)
Account2 (link)
...

So this way i will know what are all the nodes related to top node.

Basically trying to build a CRM system in drupal.

Please help me..

Gopi