Reference in cms

Good Day,
I have 4 bundles of products that vary in quantity ie bundle 1 has music and stickers, bundle 2 has music stickers and tee shirts etc. The designs on the shirts depends on the song so I have several cms fields. I am trying to link the button selected to the cms that has said button so link bundle 1 to bundle 1 cms. I put the bundles in the music track cms as a reference field but don’t know how to link the button to the bundle 1 cms etc. A bit confusing but I am trying to work out the logic. Any help would be greatly appreciated

Here is my public share link: [LINK](
(how to access public share link)