def find_specific_ner_tags(ner_parsed_sentence, target_tags):
    """ Search for target tags in a ner-ed sentence and return them.

    :param ner_parsed_sentence: A list each sentence NER's.
    :type ner_parsed_sentence: list(str)
    :param target_tags: A list with NER tags i want to find.
    :type target_tags: list(str)
    :return: list(str)
    """

    candidate_answers = []  # A list of words, which match target tags.

    # Search each pair (word, ner tag) and tag of target tags and keep only the mathces if exist.
    for word, ner_tag in ner_parsed_sentence:
        for target_tag in target_tags:
            if ner_tag == target_tag:
                candidate_answers.append(word)

    if len(candidate_answers) == 0:
        return None
    else:
        return candidate_answers