update values based on one condition

Hi All,

Here is my requirement.

COLUMN1 COLUMN2 EXPECTED RESULT COLUMN 1 X XMEN 1 Y XMEN 1 Y XMEN 2 Y NULL 2 Y NULL 3 Y XMEN 3 Y XMEN 3 X XMEN 3 X XMEN

In column2 if any records contains X value then for related records should populate as xmen.

key 1 has 3 values and it contains x, so expected result of all three should be xmen.

How can I achieve this result.