def METHOD_NAME(self, chat_id, user_id, key):
    """
    Get value for a data of a user in a chat.
    """
    response = self.get_record(chat_id)
    user_id = str(user_id)
    if response:
        if user_id in response:
            if key in response[user_id]['data']:
                return response[user_id]['data'][key]
    return None