This is really mind boggling. We have a collection that contains a collection with articles. The parent collection cannot be accessed from the articles by direct linking via navto://collection/[collectionname]?openTo=browsePage
But navto://relative/parent works. But it is always leading to the collection, even though you said it would lead to the previous article if you came there by a navto link. That is not the case.
So everything is working for us as we would like it to. But I find the behavior so strange as it differs from every documentation I read, including your posts, Bob. Does that have to do with the nested collections?