Find value n steps away from target in List with stream

To build on top of Naman's answer:

• You can directly collect to a List<String>, which is more functional.
• Also I would do the .equals test the other way in case one of the element of the list is null

Here you go:

List<String> listTwo = IntStream.range(1, listOne.size())
    .filter(i -> "test".equals(listOne.get(i))) // stream of indexes of "test" elements
    .mapToObj(i -> listOne.get(i-1))            // stream of elements at the index below
    .collect(Collectors.toList());

Something like

    IntStream.range(1, listOne.size())
            .filter(i -> listOne.get(i).equals("test"))
            .mapToObj(i -> listOne.get(i - 1))
            .forEach(item -> listTwo.add(item));