How do I pass a button value between pages and display content based on this value?

I am creating a little project at the moment for my school.
Firstly you select a school from a gallery, this takes you to the school page, You then select a year group by clicking a button. Once you click this button, I need the next page to save the button value and load it as the selected index for the dropdown that loads the content.

I hope this makes a little bit of sense.
Site in question:
https://grantwardle1997.wixsite.com/bookflicks

You can make use of the Wix Session Storage →
https://www.wix.com/corvid/reference/wix-storage/session

Tried this but hasn’t worked as expected. Tried a few variations of these as well.

@grantwardle97 Which code are you using ??