SELECT * FROM
( SELECT 'one' AS TableName, 'display' AS FieldName, display_name AS Search FROM One AS O1
UNION
SELECT 'one', 'name', name FROM One AS O2
UNION
SELECT 'two', 'display', display_name FROM Two AS T1
UNION
SELECT 'two', 'name', name FROM Two AS T2
UNION
SELECT 'three', 'display', display_name FROM Three AS T3
UNION
SELECT 'three', 'name', name FROM Three AS T4) AS TableSearch
WHERE Search = 'Word'