This week Google added a couple of frequently-requested features to Google Classroom. Those features are automatically placing the latest work at the top of the Classwork page and filtering the Classwork page by topic. Both of these features should be available to you as soon as you open your Classwork page. You can read more about both of them here.
Filtering the Classwork page according to topic comes at just the right time for end-of-year review. filtering by topic should help you and your students quickly find materials and assignments according to topic. And automatically putting new work at the top of the page should be helpful to students in not missing important and new items.