To maintain the scenario scope for an end-user please run transaction SA38 and execute report /IMA/SCOPE_SEL_CUSTOMIZING to add an entry to table /IMA/SCOPECUSTOM.
Enter one entry for each end-user/entity combination.
Please note that you need to assign at least one scenario, technical system or cloud service to an end-user to trigger the mechanism. End-users, who have no entry in this table can see all scenarios, technical systems and cloud services.