Data puzzle with great value!

[ssjordan95]

Hello! I am new to Power BI and trying to do somethign quite complicated - or so I believe. I have two columns, one with let's say 'numbers X'. I have another column with let's say 'numbers Y'. I would like to return all X values with the same Y value for selected values in column 'numbers X', but not returning a repeat within a selected value from 'numbers X'. The issue I am running into is the lookup function is returning a repeat selected value for itself. See example below. '1' and '2' would be returned because it was found with same 'numbers Y'. '4' would not be returned because 'numbers Y' did not have a repeat value outside of itself. 

numbers X	numbers Y	Selected Values (drop down of 'numbers X')	Results ('numbers X' with same values in 'numbers Y')
1	10	1	1
1	12	2	2
1	10	4
2	10
2	15
2	13
3	10
3	9
3	6
4	7
4	27
4	9
4	7

[tamerj1 · Accepted solution]

Hi @ssjordan95 
Please find attached sample file with the solution

Filter Measure = 
VAR T1 = 
    VALUES ( 'Table'[numbers Y] )
VAR T2 = 
    CALCULATETABLE ( 
        VALUES ( 'Table'[numbers Y] ),
        EXCEPT ( ALLSELECTED ( 'Table'[numbers X] ), VALUES ( 'Table'[numbers X] ) )
    )
VAR T3 =
    INTERSECT ( T1, T2 )
RETURN
    IF ( 
        NOT ISEMPTY ( T3 ),
        1
    )

[ssjordan95]

Thank you very much! If I could give you a hug, I would.