Hierarchy Row Level Authorization
I need to apply rowlevel security at every node of an hierarchy....To clear the requirement more, Say I have 1000 users and the geography hierarchy is of 5 level like Region->Country->City->District->Branch…..L1,L2,L3,L4,L5 resp...say for example we need row level security to 5 levels in hierarchy. L1, L2, L3 , L4, L5. L1 being at top in hierarchy. now the issue is L1 has 6 values, L2 has 20, L3 has around 20, L4 has around 14 and L5 has around 13. now the unique combination is running around in 20k+. what is the best approach to do so?