IF (aggr(rank( sum(Value) ,0) , Value )> 5 , sum(Value) )

[#1]

explination pls  how it is working 

IF (aggr(rank( sum(Value) ,0) , Value )> 5 , sum(Value) )     

[#2]

IF (aggr(rank( sum(Value) ,0) , AnyDimension)> 5 , sum(Value) )    

It makes the sum of value only if its rank (of the sum(Value) aggregated for AnyDimension) is >5 (ex. 6th,7th,...)