Check for matching group in two separate tables

Hey ddorhout ,

that is possible.

Please check the following calculated column. I wrote the comments what exactly is going on in the formula:

Result = 
-- the User of the current row
VAR vUserCurrentRow = 'Table 1'[Column 1]

-- the Item of the current row
VAR vItemCurrentRow = 'Table 1'[Column 2]

-- Filter of Table 2 to the current user and selection of the related groups
VAR vTableGroupUser =
    SELECTCOLUMNS(
        FILTER(
            'Table 2',
            'Table 2'[Column X] = vUserCurrentRow
        ),
        "@Group", 'Table 2'[Column Y]
    )

-- Filter of Table 3 to the current item and selection of the related groups
VAR vTableGroupItem =
    SELECTCOLUMNS(
        FILTER(
            'Table 3',
            'Table 3'[Column A] = vItemCurrentRow
        ),
        "@Group", 'Table 3'[Column B]
    )

-- Intersection of the two tables. If there is a group in table 2 for the current user
-- and group in table 3 for the current item we find a match here
VAR vIntersection =
    INTERSECT(
        vTableGroupUser,
        vTableGroupItem
    )

-- we count if there is a match / if one row is left after the intersection
VAR vAmountRowsIntersection =
    COUNTROWS( vIntersection )

RETURN

-- If there is row we return "Yes", otherwiese "no"
    IF(
        vAmountRowsIntersection > 0,
        "Yes",
        "No"
    )

The result is identical to your desired result: