Challenges with roles/employee access for project reporting

Here's my quandary - and I will try to provide details to make it understandable.

My reporting is needed at a project level.  I need directors/managers/admins to have access to the project, or projects, that they are involved in - but do not want them to have access to the data on projects of others.

Netsuite allows access to be restricted by
1) department,
2) class (which we changed to a managerial hierarchy) and
3) location (which we have made a project type and actual project hierarchy in order to be able to have inventory by project).

The problem is that we do not have a linear reporting hierararchy (sometimes a manager reports to multiple directors) and a project's management can change (managers come and go) - making the access to historical data a nightmare.