If we are always going to be limited to 3 filter rules (or 8 rules for schedule filters) then i would like to have the ability to "stack" filters.
Essentially - now that the "or" has been added to the roadmap (see http://forums.autodesk.com/t5/revit-ideas/quot-or-quot-in-filter-rules/idi-p/6322629 ) then we may need more rules to define Case A OR Case B.
Currently - you set categories to test against the filter you are creating - then you pick a parameter that elements of that category could contain - then a test (equals, begins with, etc) - and you get a Yes/N0
Enter the filter within a filter - adding in a rule test of "Passes Filter" or "Does Not Pass Filter". So this would be in addition to the current rules capabilities - instead of picking a parameter to test if it equals or starts with or contains, you pick a Filter - then choose to test whether the elements in the category pass or do not pass the filter.
Example:
I have a filter for Concrete Walls, CMU walls, Loadbearing Walls, Shear Walls,
Suppose i want to create a filter that would pass all concrete and cmu loadbearing shear walls but exclude wood shear walls, metal stud shear walls, cmu non-loadbearing infill walls, and non-shear concrete walls.. There's a lot of rules required to test all that - and they wont fit in the current 3 (or perhaps even the schedule 8). (Not to mention that re-entering most of those rules i've already created makes little sense). If i could simply leverage the existing filters i've already got in the creation of my new filter by testing if the pass a set of filters - it would make things much faster/cleaner.
