NWDI doubts

Hello People

I Have unique authorization requirement for SAP XI Version 7.0 SP6 (ABAP/JAVA) STACK. The costumer wants to use one XI instance for the whole company; this means, different business scenery projects using the same XI instance. The authorization requirements is to create a security mechanism to protect every business scenery distinctly

For example:

One group of developers can only work in your specific scenary and can't touch or see the development of another project

In the same project May I give especific and different authorizations for each member of the same group

Thanks a lot