From CRM 1.5.1 it's possible to set parent- child relations between companies.
You should use Company attributes with types Parent Company and Child Companies for that.
You can't see the hierarchy tree for companies yet. But with Child Companies attribute you can see a list of child companies for some company.
Currently parent-child relations may affect only issue security. We added a new level of JIRA Issue Security - Holding employees.
If set, then all contacts from all parent and child companies will be able to see some issue, that was reported by some employee from the holding.
For example, we have:
1) Company 1 with Contact A
2) Company 2 with Contact B
3) Company 3 with Contact C
4) Company 4 with Contact D
Company 1 is parent for Company 2. Company 2 is parent for Company 3.
If Holding security is set, then Contact A and Contact C will be able to see an issue reported by Contact B.
And Contact D won't be able (unless he has some other role for the issue, mentioned in issue security).
To set companies hierarchy and Holding employees security level, do the next steps: