Separating and Displaying Posts/Pages

Hi WordPress Friends,

I have built a couple of sites for the schools and now they want to archive previous classrooms, but that they still would be accessible for the parent to go back and view what their kids has done for example for Ms Mary First Class in 2014, but would not be shown inside of the existing classroom pages and that archive page would not show existing content from current classrooms?

I have tried several hacks/plugins, but they all are no good. Some of them just hides content, others just display the whole lot in one bunch.

I am pretty sure that someone else has came across something similar?

Thanks in advance.

Jonas