Top 3 Customers for each Cohort

[tomislav_mi]

Hey guys,

Can I get please help on this:

I am struggling to get Rank of Top 3 customers (based on sales) within each Cohort. 
I have been trying to get calculated column like in the example (highlighted orange) but always stopping somewhere.

If there is some way how to get a measure that can serve as a filter it could also be great.

Data looks like this:

Customer	ReportDate	LifetimeMonth	Cohort	Sales	Top3
A	1/31/2020	1	01-2020	200	3
A	2/29/2020	2	01-2020	200
A	3/31/2020	3	01-2020	300
A	4/30/2020	4	01-2020	300
A	5/31/2020	5	01-2020	300
B	1/31/2020	1	01-2020	600	1
B	2/29/2020	2	01-2020	500
B	3/31/2020	3	01-2020	500
B	4/30/2020	4	01-2020	500
B	5/31/2020	5	01-2020	500
B	6/30/2020	6	01-2020	500	2
C	1/31/2020	1	01-2020	350
C	2/29/2020	2	01-2020	350
C	3/31/2020	3	01-2020	350
C	4/30/2020	4	01-2020	250
DDD	5/31/2018	1	05-2018	58	2
DDD	6/30/2018	2	05-2018	68
eee	5/31/2018	1	05-2018	14	3
eee	6/30/2018	2	05-2018	14
fff	5/31/2018	1	05-2018	300	1
fff	6/30/2018	2	05-2018	600

Hope there is someone who can help!

Thank you all!

[Greg_Deckler]

I believe I have some examples like that here:

https://community.powerbi.com/t5/Quick-Measures-Gallery/To-Bleep-with-RANKX/m-p/1042520#M452