JAVA XML - 如何在XML节点中获取特定元素？

This is an academic assignment and we are given an extremely large XML file with hundreds of entries like these. For each item we are supposed to list the Manager's ID, the Person's ID of the last person to add an item to the list, and the current number of items. I have read and reread the Oracle DOM API and various Node APIs. We are using JAVA and I cannot for the life of me figure out how to search various 'fields' of each This is an academic assignment and we are given