You can look for items in the library by library folder or by topic. Go to "View by: Topic" to see the topic-related display.
You can also type a search term into the search box. Go to "Advanced Search" for more options. In Advanced Search you can target your search by a particular topic, by the type of resource, such as news item, calendar event, etc., or by the date it was posted or a range of time during which it was posted.