As a teacher I can see my students progress and achievements. But my students can't see each other information or compare progress with their colleagues. Is there a dashboard (student view) of the class? How can I access it?
No, there is no way for students to view their progress like you can in the dashboard. They can view each other's levels and xp if the follow each other.
You may also want to move this to the educators forum, instead of troubleshooting. This way, Staff who works on Duolingo for schools can see your awesome idea, and people who need technical assistance will hopefully get help faster, because the troubleshooting forum is intended for glitch reports.
The way they can do this is by "following" each other, they would then be able to compare their scores on the leaderboard. Some teachers also mention that their students enjoy it when they project the progress view on the Smartboard or projector. :]