Changing Header Row Every Year

[Annu2847_A]

Each Year will get a new File with the New Year-Month as a header Row.   

How to Unpivot the data. 

Sample Data :  

Key	Jan-23	Feb-23	Mar-23	Apr-23
AA1	454	46	67	778
AA2	54	123	7545	57
AA3	6564	56	656	656
AA4	34	245	657	55
AA5	2342	34	23	54
AA6	56	12	354	454
AA7	787	5464	123	123
AA8	234	57	56	679

Key	Jan-24	Feb-24	Mar-24	Apr-24
AA1	54	43	545	778
AA2	545	6	3423	3
AA3	65	56	656	656
AA4	34	7	23	7776
AA5	2342	56	34	54
AA6	6	7	354	454
AA7	787	4545	434	43
AA8	234	57	56	34

[wdx223_Daniel]

=Table.UnpiovtOtherColumns(PreviousStepName,{"Key"},"MonthYear","Value")

[Annu2847_A]

Thanks @wdx223_Daniel / for the Response.   

The Above I have already tried but,  But I feel this doesn't work when another file comes in into  same dataset.  for another Year.  

If you see below i have exported 2 year of Data,  but even if i will make first row as header , In the Header Row will have year 2023,  But same will get unpivoted.   Even Year 2024 Data will get unpivoted with 2023 only.  

That's where i am facing the issue. in the same dataset every year , i have add the files, But Header Row has to be changed every year.   

[wdx223_Daniel]

=Table.Combine(Table.Group(PreviousStepName,"Column1",{"n",each  Table.RenameColumns(Table.UnpivotOtherColumns(Table.PromoteHeaders(_),List.FirstN(Record.ToList(_{0}),2),"Date","Value"),{Record.ToList(_{0}){0},Table.ColumnNames(_){0}})})[n])

[JP_Wisco]

It looks like you are combining files from multiple years. You will want to apply the unpivot recommended by @wdx223_Daniel to your sample transformation query. You can then hop back into your main query after the files are combined and repivot or transform however you need.