Hi Karya,
Yes, this will limit only he actual permissions, but then you need new user roles instead of all the existing standard NAV roles, which surely is not something I would recommend anyone (unless you have a tool supporting you like NAV Easy Security or similar). And what the question poster really wants is to remove the departments menu from the users. But yes, they should also limit the permissions to actually see the financial entries, otherwise the users could go through the “back-door”, like go from Sales Lines to G/L Accounts and here see all the G/L Entries in the system (after removing the G/L Account No. filter).