Custom Column to Lookup Multiple Fields in Other Table and Return Match within Date Range

Hi, ChelseaCL 

a quick conversion from gpt

go to add a custom column then paste this code below. Please adjust the Previous step name first. Or it will show error. 

= Table.AddColumn(#"PreviousStepName", "Contract Index", each 
    let
        _startdate = List.First(
            Table.Column(
                Table.SelectRows(Contracts, 
                    each [Company] = [Company] and [Software] = [Software]
                ), "Start Date"
            )
        ),
        _enddate = List.First(
            Table.Column(
                Table.SelectRows(Contracts, 
                    each [Company] = [Company] and [Software] = [Software]
                ), "End Date"
            )
        ),
        _indates = [Accessed] >= _startdate and [Accessed] <= _enddate,
        _indexnumber = List.First(
            Table.Column(
                Table.SelectRows(Contracts, 
                    each [Company] = [Company] and [Software] = [Software]
                ), "Index Number"
            )
        )
    in
        if _indates then _indexnumber else null
)