Re: Part of the revenue coming from the top 1% of the customers (top1% in volume)
I would start with something like this (assuming vRankMax is defined with a leading equal sign and evaluated to a number):
If( Rank( Sum(Income)) <= vRankMax, Sum(Income)),
Customer, Business, FiscalYear
Adapt the aggr() dimensions to the required granularity for the rank.
Then you should be able to use above expression e.g. in a chart with dimensions Business and FiscalYear.
If you want to use a set expression, you would need to create and define keys with the required granularity for the field modifier with the ranking search,Customer alone is probably not granular enough.
If your chart dimensions are less granular than the aggr() dimensions, the results of the aggr() function will be projected to the chart dimensions, using the outer aggregation function ( Sum() ), i.e. all Customer Income above threshold per Businees A and per fiscal year will be grouped by fiscal year and summed.