Revisiting a slide after knowledge check

Hi there,

I am working on a training and have a section where users need to visit 12 different slides in order to proceed. Once they do, they will start a few knowledge check questions. Those knowledge checks will direct them back to specific parts of the training to review. Normally the button they would pick would direct them back to the menu of the 12 slides they need to visit, but I'd like them to be directed back to the knowledge check. 

I tried doing a variable where when the timeline starts on the knowledge check that the layer of the other slide (with a new next button) would show. This is only my 2nd time creating anything in Storyline, so I am definitely in need of some help. 

I can probably only share a file with a staff member privately.

Thank you!