Feel free to review the options available in Access rights and authorizations before using this module.
However, you can limit the access to a project, sub-project or company for a certain group of people with the module Exclusive Members module when looking at the company/project/subproject screen or the Exclusive Member Of module, when looking at the person screen.
The project, sub-project or company will now only appear for these members in the timesheet module drop down list.
To start using the Exclusive Members module:
You can add employees one by one using the Add a new person button or directly add a larger population by selecting an existing group of employees by clicking on Add groups. (To know more about Groups)