In the Modules view, the items in the list can be expanded to show compile units, files, and functions. When you are viewing modules, clicking the Show modules with debug information button will filter out those modules without debug information, leaving only the modules with debug information. By default, this setting is on.
When inspecting modules, double-clicking source file nodes will cause the source to open in the editor.
You can have the properties of compile units, files, and functions displayed in the Properties view, as follows: