The Dungeon only shows progress. It's not a way to share your wip with others, trusted friends or not. You can post an excerpt if you want, but that's mainly for agents or editors who are perusing the public areas of the site to get a feel for your wip and then only if you have it marked visible. The Dungeon is mainly a progress tracking tool. Hope that helps explain it!

We are however working on a Crit Pond that we hope to launch soon which will enable to have granular control over who can read and critique your manuscript. Totally separate thing though.