Current
let
    Source = Excel.CurrentWorkbook(){[Name="Cur"]}[Content],
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"CurPart", type text}}),
    CurName = #"Changed Type"{0}[CurPart]
in
    CurName

Previous
let
    Source = Excel.CurrentWorkbook(){[Name="Prev"]}[Content],
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"PrevPart", type text}}),
    PrevName = #"Changed Type"{0}[PrevPart]
in
    PrevName

SubCon1
let
    Source = Excel.CurrentWorkbook(){[Name="Suba"]}[Content],
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"SubConTit1", type text}}),
    SubNameA = #"Changed Type"{0}[SubConTit1]
in
    SubNameA

SubCon2
let
    Source = Excel.CurrentWorkbook(){[Name="Subb"]}[Content],
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"SubConTit2", type text}}),
    SubNameB = #"Changed Type"{0}[SubConTit2]
in
    SubNameB