Group Data to Summarize Table in DAX to Concatenate Values

[newpbiuser01]

Hello,

I have the following table where the Previous Month-Year column is a calculated column. and I'm trying to summarize the table by each vendor and the month-year.

Vendor	Month-Year	Type	Previous Month-Year
A	2-2021	Debit Card	1-2021
A	2-2021	Credit Card	1-2021
B	3-2021	Debit Card	2-2021
C	5-2021	Credit Card	4-2021
D	1-2022	Credit Card	12-2021
E	2-2022	Check	1-2022
B	9-2023	Check	8-2023
C	7-2021	Credit Card	6-2021
D	11-2022	Debit Card	10-2022
A	8-2023	Check	7-2023
B	12-2022	Credit Card	11-2022
C	7-2023	Debit Card	6-2023
D	8-2021	Check	7-2021
B	1-2023	Debit Card	12-2022

I tried doing it as a calculated column to get a concatenated list for the current month based on the month-year column and then another calculated column to get a concatenated list for the previous month based on the previous month-year column as follows:

Current Month Payment Type = 

    CALCULATE(CONCATENATEX(VALUES( 'Table'[Type]),'Table'[Type], ","), FILTER('Table', AND([Vendor] = EARLIER([Vendor]), [Month-Year] = EARLIER([Month-Year]))))

Previous Month Payment Type = 

    CALCULATE(CONCATENATEX(VALUES( 'Table'[Type]),'Table'[Type], ","), FILTER('Table', AND([Vendor] = EARLIER([Vendor]), [Month-Year] = EARLIER([Previous Month-Year]))))

However, I keep getting a circular dependency error. When I try doing it as a measure as follows:

Payment Type - Previous Month  = 

    CALCULATE(CONCATENATEX(VALUES( 'Table'[Type]),'Table'[Type], ","), FILTER('Table', [Month-Year] = [Previous Month-Year]))

I get a blank. What am I doing wrong? My goal is to have a table that shows

 

Vendor	Month-Year	Previous Month-Year	Current Month Payment Type	Previous Month Payment Type
A	2-2021	1-2021	Debit Card, Credit Card
B	3-2021	2-2021	Debit Card	Debit Card, Credit Card
C	5-2021	4-2021	Credit Card
D	1-2022	12-2021	Credit Card
E	2-2022	1-2022	Check	Credit Card
B	9-2023	8-2023	Check	Check
C	7-2021	6-2021	Credit Card
D	11-2022	10-2022	Debit Card
A	8-2023	7-2023	Check	Debit Card
B	12-2022	11-2022	Credit Card	Debit Card

I appreciate any help!

[ryan_mayu]

@newpbiuser01 

is this what you want?

Table 2 = 
var tbl=SUMMARIZE('Table','Table'[Vendor],'Table'[Month-Year],"current type",CONCATENATEX('Table',[Type],","),"previous",EDATE('Table'[Month-Year],-1))
var tbl2=ADDCOLUMNS(tbl,"previous type",maxx(FILTER(tbl,'Table'[Vendor]=EARLIER('Table'[Vendor])&&'Table'[Month-Year]=EARLIER([previous])),[current type]))
return tbl2

pls see the attachment below