Compare columns based on two different table

SBC Do this in PowerQuery and use 2 columns as a key when merging queries.

let
    Source = Table.NestedJoin (
        T1,
        { "member  ", "deal  " },
        T2,
        { "member   ", "Deal " },
        "T2",
        JoinKind.FullOuter
    ),
    ExpandedT2 = Table.ExpandTableColumn (
        Source,
        "T2",
        { "member   ", "Deal ", "Qty", "Date" },
        { "member   ", "Deal ", "Qty.1", "Date.1" }
    )
in
    ExpandedT2

If you want a full outer join with DAX you can read this and modify yourself: https://www.antmanbi.com/post/full-outer-join-in-dax-in-power-bi-and-ssas-tabular