Converting quarter data into months

Hi ch_metglobal 

With "Your_Source"

let
Source = Your_Source,
Transform = Table.TransformColumns(Source,
   {{"YYYYQN", (x) => List.Transform({1, 2, 3}, 
       each #date(Number.From(Text.Start(x,4)), (Number.From(Text.End(x,1))-1)*3+_, 15)), type list},
    {"Value", each _ /3, type number}}),
Expand = Table.ExpandListColumn(Transform, "YYYYQN")
in
Expand

 Stéphane

Given your data:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WSlTSUTIyMDINNAQyLI2VYnWQxIyADEMDVDFjIMPUAlXMBMgwg6hLQjEPTQxknokpqhjIPAs0dSZge82VYmMB", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column1 = _t, Quarter = _t, Amount = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", type text}, {"Quarter", type text}, {"Amount", Int64.Type}}),
    #"Grouped Rows" = Table.Group(#"Changed Type", {"Column1","Quarter"}, {
        {"Monthly", (t)=>
            [a=List.Sum(t[Amount]) / 3,
             b=#date(Number.From(Text.Start(t[Quarter]{0},4)), (Number.From(Text.End(t[Quarter]{0},1))-1)*3+1,15 ),
             c=List.Accumulate({0..2},{},(s,c)=> s & {Date.AddMonths(b,c)}),
             d=List.Transform(List.Zip({c, List.Repeat({a},3)}), each Record.FromList(_,{"Date","Amount"}))
             
             ][d], type {[Date=date, Amount=number]}
            
            }}),
    #"Expanded Monthly" = Table.ExpandListColumn(#"Grouped Rows", "Monthly"),
    #"Removed Columns" = Table.RemoveColumns(#"Expanded Monthly",{"Quarter"}),
    #"Expanded Monthly1" = Table.ExpandRecordColumn(#"Removed Columns", "Monthly", {"Date", "Amount"})
in
    #"Expanded Monthly1"

Produces:

NewStep=#table(Table.ColumnNames(YourSourceName),List.TransfromMany(Table.ToRows(YourSourceName),each let a=Text.Split(_{1},"Q") in List.Transform({1..3},each #date(Number.From(a{0}),Number.From(a{1})*3-3+_,15)),(x,y)=>{x{0},y,x{2}/3}))