Power Query: Duplicate Rows, MONTH(TODAY()), and Add to Month For Duplicated Rows

Jpalaci1 

Practically the same as NicolasTld  explained, in terms of generated scripts

Data

let
    thisMonth = Date.StartOfMonth( Date.From( DateTime.LocalNow() ) ),
    Source = Excel.CurrentWorkbook(){[Name="Data"]}[Content],
    dataMonth = Table.AddColumn(Source, "dataMonth", each #date([Year], [Month], 1)),
    Filter1 = Table.AddColumn(dataMonth, "Filter1", each [dataMonth] < thisMonth),
    Filter2 = Table.AddColumn(Filter1, "Filter2", each [dataMonth] = thisMonth)
in
    Filter2

Previous:

let
    Source = Data,
    #"Filtered Rows" = Table.SelectRows(Source, each ([Filter1] = true)),
    RemoveFilters = Table.RemoveColumns(#"Filtered Rows",{"dataMonth", "Filter1", "Filter2"})
in
    RemoveFilters

Current:

let
    Source = Data,
    FilterCurrent = Table.SelectRows(Source, each ([Filter2] = true)),
    RemoveFilters = Table.RemoveColumns(FilterCurrent,{ "dataMonth", "Filter1", "Filter2"})
in
    RemoveFilters

Future:

let
    thisMonth = Date.StartOfMonth( Date.From( DateTime.LocalNow() ) ),
    thisMonthNumber = Date.Month( thisMonth ),
    otherMonths = {thisMonthNumber+1 .. 12},
    Source = Data,
    FilterCurrent = Table.SelectRows(Source, each ([Filter2] = true)),
    RemoveFilters = Table.RemoveColumns(FilterCurrent,{"Month", "dataMonth", "Filter1", "Filter2"}),
    AddMonths = Table.AddColumn(RemoveFilters, "Month", each otherMonths),
    Duplicate = Table.ExpandListColumn(AddMonths, "Month")
in
    Duplicate

fullYear:

let
    Source = Table.Combine({Previous, Current, Future})
in
    Source

Hello Jpalaci1 !

Step 1 :

1.  Filter 1 :
   • I recommend you to add TODAY() formula in a cell in your worksheet. Then, load this range in Power Query (Select your cell, click on "Data" > "From table"). Today date will be now loaded into Power Query.
   • To use it properly, you will have to add "{0}[Column1]" (drill down) to get a value and not a table. It should look like this "Date.From(Excel.CurrentWorkbook(){[Name="Today_date"]}[Content]{0}[Column1])". 
   • Rename it "Today_date" and use this date for your filter > Table.SelectRows(Step, each [Month]>= Date.Month(Today_date))
2. Filter 2 :
   • Use Date.Month(Today_date) to help you perform this filter

Step 2 & 3 :

1. Step 2 :
   • if you want to duplicate rows for each month, you can create for each row a list which contains month number from month +1 to 12. Example : {1..12} creates a list from 1 to 12.
   • You can use "AddColumn = Table.AddColumn(PreviousStep, "List", each {[Month]+1..12})". You will have a list from Month +1 to 12 in each Row.
   • Then, Expand this new column by using "ExpandColumn = = Table.ExpandListColumn(AddColumn, "List").
2. Step 3 :
   • I don't understand what you would like to do. You can use the same list creation as explained in step 2 to duplicate rows (with {1..12}).

In order to append step 1a, step 2 and step 3 into one table, you can simply use Table.Combine (more info here : https://docs.microsoft.com/fr-fr/powerquery-m/table-combine)

Step4 = Table.Combine({"Step1", "Step2", "Step3")}

Hope it will help,

Nicolas