Setting up hidden filters
Hidden filters are a new feature from version 5.5 that allows us to show dynamic and static diagrams as well as reports, while filtering all the results based on which group the user belongs to. It is basically an alternative to generating a lot of diagrams/reports each with individual filters. With hidden filters it is possible to do the same with just one instance of a report or a diagram. An example could be that you want to show the gender segregation of the department a user comes from. We can then add one hidden filter for each department (where department is a group where the user is member) and specify a filter that ensures only showing the result from that department, like 'Department==12'. Since we cannot be sure that a user only belongs to one of the specified groups, it is necessary to index the hidden filters. If a user viewing the report or diagram then belongs to more than one of the stated groups, he will only get the diagram/report he is viewing filtered on the highest indexed hidden filter (the one placed highest on the list). If the logged in user does not belong to any of the groups/users of the hidden filter list, then no hidden filter will be applied. Hidden filters are always combined with other types of external filters.
