At Actions -> Pages, urls are displayed in hierarchy, and "open transition" and "open overlay" links only showed at the urls like this.
I'm using ref parameters to track users' click, and can't open transition and overlay directly.
I have to open the overlay view from other links then navigate to the page I want to see, and open transition view from there.
Is excluding the ref parameter an option for you? See http://piwik.org/faq/how-to/faq_81/ . All the URLs under
node/1/?ref= would be merged together as one pageview