OpenERP7
A user with Access Rights:
Sales: See Own Leads can see (not edit) the customers.
On other version, this user can only see the partners assigned to this user or not assigneds to any user.
OpenERP7 show all clients, but you can create a record rule to modify this behavior.
Other / Contact creation checked: can edit the partner assigned to the user (or without user assigned)
If you have a multicompany environment, the users can only see the records of the actual company selected to user (under preferences) or some record without company assigned or if the object/record company is child of the company user.
i.e: Can see all customers with match the company of user with the company of partner OR the customers with no assigned company (you can see also the records if the partner company is child of the user company)
To see the fields relative to multicompany and assign perms on user configuration, you need to check Manage multiple companies under General settings.
The user allowed to use multicompany, should have the access rights:
Usability / Multi Companies checked
(dont remember to check this to the user Admin).
Now you can see a field named Allowed Companies on user config to determine what companies are allowed to this user.
On some objects you can see a field named Company to determine the visibility of the record.
Maybe this help you!