It's easy to group supply lists in Pages.
On the page, enter the name of the first group in a Content block
To make the group name stand out more on the page, highlight the text and format it as "Header 2"
Add a supply list block. Select the lists in this group and save
Change the order of lists in this group using the 6-dots icon to drag and drop lists
Repeat steps 1 - 3 for each group and Publish the page
Families will quickly be able to find the supply lists for their students on the public page