CREATE TABLE table_19183 ("Home  ( 1st leg ) " TEXT, "Home  ( 2nd leg ) " TEXT, "1st Leg" TEXT, "2nd leg" TEXT, "Aggregate" TEXT)

Who was in 2nd leg when Boca Juniors was in home (1st leg)?
SELECT "2nd leg" FROM table_19183 WHERE "Home (1st leg)" = 'Boca Juniors'
SELECT "2nd leg" FROM "table_19183" WHERE "Home (1st leg)" = 'Boca Juniors'