In courses

The navigation inside the course area corresponds to an index file with tabs.

There are main categories — they are represented by the tabs. One tab is always active in the foreground (in this example Overview) and offers several subcategories (in this case: Brief information, Details, etc.)

You only reach the respective subcategories if you have previously activated the right tabs.

You change between the tabs and the subitems by clicking on the respective words.