how to control project data update by other department

Hi,

I have a requirement to restrict 1) update projects information & 2) view data of projects created by Department A by department B.

These two departments access projects, budgets, invoices information in PA from their own responsibilities. Have separate menus for each of their responsibilities. Both department's responsibilities under same ledger.

We already implemented MO: security profile to access multiple organizations with out switching responsibilities.

Department A  PM responsibility has access 'projects' form to create his projects with department A templates. Department B ha also has access to same 'projects' form, though access this form, is from dept. B responsibility. Since the form is same, to create, query projects, and both depts. PMs require to create projects, managed cost budgets etc.., functions.., checking the way to restrict view dept A projects info to dept B OR at least, dept B PM should not be able update dept A projects.