Rank and aggregate on multiple set analyses

[#1]

Hi everyone,

Got an issue here, currently am using the below expression in order to rank top 10 sales by only closed orders.

=aggr(if(rank(fabs(ONLY({$<[Closed Sale]={1}>}[Sales])))<=10,[Account Name]),[Account Name])

My question is, I am trying to do this for ONLY the last month. 

When i create a flag for the last month and intersect it with the closed sale set expression however, it only picks out those from the initial top 10 ranking which are in the last month set.

I need it to rank the top 10 sales for the previous month (Same as clicking on that month and seeing the top 10) by default.

Any help is much appreciated.

Thanks