Filtering table by other table,

Hi, Irek 

First, create a new table:

Table 2 = SELECTCOLUMNS('Table',"Name2",'Table'[Name])

Then create a new measure and try the following DAX:

Measure = 
VAR _Slicer =
    VALUES ( 'Table 2'[Name2])
VAR _vtable =
    ADDCOLUMNS (
        GENERATE ( 'Table', _Slicer ),
        "AAA", IF ( FIND ( [Name2], [Key],, BLANK () ) <> BLANK (), [Name2] )
    )
VAR _vtable2 =
    SUMMARIZE (
        _vtable,
        [Key],
        "BBB",
            IF (
                LEN ( CONCATENATEX ( _Slicer, [Name2] ) )
                    = LEN (
                        CONCATENATEX ( FILTER ( _vtable, [Key] = EARLIER ( [Key] ) ), [AAA] )
                    ),
                CONCATENATEX ( FILTER ( _vtable, [Key] = EARLIER ( [Key])), [AAA] )
            )
    )
RETURN

    IF (
        CONCATENATEX ( FILTER ( _vtable2, [Key] = 'Table'[Key]), [BBB] )
            <> BLANK (),
        CONCATENATEX ( FILTER ( _vtable2, [Key] = 'Table'[Key] ), [BBB] )
    )

When you select Bob, here is preview:

Then select Adam:

How to Get Your Question Answered Quickly

Best Regards

Yongkang Hua

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.