HomePage customised to select Service Groups need to filter sidebar

I have a requirement to filter the Service Catalog Groups based on subgroupings on the Sidebar. I understand I need to do this based on the Tile the user clicks on the homepage. Clicking on this html tile brings me to the Service Catalog screen.

I know I need to use jQuery to filter the attributes down but

1. How can I capture the tile that was selected on the previous screen on the previous screen
2. How can I populate a custom attribute to create a subgroup of Service Categories which the jQuery can filter on.

Regards

Stephen