Handling Excel Matrixed Data

Is it your required format? workingdataprep 

let
    Source = Excel.CurrentWorkbook(){[Name="Table1"]}[Content],
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", type text}, {"Column2", type text}, {"Column3", type any}, {"Column4", type any}, {"Column5", type any}, {"Column6", type any}, {"Column7", type any}, {"Column8", type any}}),
    #"Transposed Table" = Table.Transpose(#"Changed Type"),
    #"Filled Down" = Table.FillDown(#"Transposed Table",{"Column1"}),
    #"Merged Columns" = Table.CombineColumns(#"Filled Down",{"Column1", "Column2"},Combiner.CombineTextByDelimiter("||", QuoteStyle.None),"Merged"),
    #"Transposed Table1" = Table.Transpose(#"Merged Columns"),
    #"Promoted Headers" = Table.PromoteHeaders(#"Transposed Table1", [PromoteAllScalars=true]),
    #"Changed Type1" = Table.TransformColumnTypes(#"Promoted Headers",{{"Type||", type text}, {"Category||", type text}, {"Jan 1 - Jan 30||Actual", Int64.Type}, {"Jan 1 - Jan 30||Planned", Int64.Type}, {"Feb 1 - Feb 28||Actual", Int64.Type}, {"Feb 1 - Feb 28||Planned", Int64.Type}, {"Mar 1 - Mar 30||Actual", Int64.Type}, {"Mar 1 - Mar 30||Planned", Int64.Type}}),
    #"Unpivoted Other Columns" = Table.UnpivotOtherColumns(#"Changed Type1", {"Type||", "Category||"}, "Attribute", "Value"),
    #"Split Column by Delimiter" = Table.SplitColumn(#"Unpivoted Other Columns", "Attribute", Splitter.SplitTextByDelimiter("||", QuoteStyle.Csv), {"Attribute.1", "Attribute.2"}),
    #"Changed Type2" = Table.TransformColumnTypes(#"Split Column by Delimiter",{{"Attribute.1", type text}, {"Attribute.2", type text}}),
    #"Renamed Columns" = Table.RenameColumns(#"Changed Type2",{{"Type||", "Type"}, {"Category||", "Category"}, {"Attribute.1", "Date Range"}, {"Attribute.2", "Actual vs Planned"}, {"Value", "Sales Amount"}})
in
    #"Renamed Columns"

I’m assuming the dataset is quite simple. However, if you’re working with a larger dataset, you’ll need to handle the nested headers separately.