Comparing Two columns with Output (Parent and Child relation)

Hi Hanuma_Srikiran

Try this Calculated Table.

New Table =
VAR AllParent =
    SELECTCOLUMNS ( TableName, "AllParents", TableName[Parent] )
VAR Firstparent =
    ADDCOLUMNS (
        EXCEPT ( ALL ( TableName[Child] ), ALL ( TableName[Parent] ) ),
        "FirstParent", CALCULATE ( VALUES ( TableName[Parent] ) )
    )
VAR secondparent =
    ADDCOLUMNS (
        SELECTCOLUMNS (
            Firstparent,
            "LastChild", [Child],
            "FirstParent", [FirstParent]
        ),
        "SecondParent", LOOKUPVALUE ( TableName[Parent], TableName[Child], [FirstParent] )
    )
VAR thirdparent =
    ADDCOLUMNS (
        SUMMARIZE ( secondparent, [LastChild], [FirstParent], [SecondParent] ),
        "ThirdParent", LOOKUPVALUE ( TableName[Parent], TableName[Child], [SecondParent] )
    )
VAR Fourthparent =
    ADDCOLUMNS (
        SUMMARIZE (
            thirdparent,
            [LastChild],
            [FirstParent],
            [SecondParent],
            [ThirdParent]
        ),
        "FourthParent", LOOKUPVALUE ( TableName[Parent], TableName[Child], [ThirdParent] )
    )
RETURN
    FILTER (
        UNION (
            SUMMARIZE ( Fourthparent, [LastChild], [FirstParent] ),
            SUMMARIZE ( Fourthparent, [LastChild], [SecondParent] ),
            SUMMARIZE ( Fourthparent, [LastChild], [ThirdParent] ),
            SUMMARIZE ( Fourthparent, [LastChild], [FourthParent] )
        ),
        [FirstParent] <> BLANK ()
    )