eg. https://musicbrainz.org/cdtoc/attach?id=aIIi.K3ZTGtgyTt0hdqTdAdJmJI-&tracks=9&toc=1+9+313012+150+31845+59960+87600+127910+162590+189750+246110+287782

shows 3 releases but say my cd is https://musicbrainz.org/release/1af9e5bc-95ee-4e2a-a04a-b0b7dbeaaf73

Between "We used DiscID aIIi.K3ZTGtgyTt0hdqTdAdJmJI- to look up this information." and "Search by artist" add

"Same release group(s)" {with the structure from the following search screen} ie.

Release      Artist      Country/Date      Label      Catalog#     Barcode      Tagger             Release Group: Piano Concertos nos. 1, 2 / Violin Concerto, op, 64

Piano Con  Mendels  US 1991             Sony Cl  SBK 46542   07464465  TAGGER

    O cd 1 (show tracklist)

Attach CD TOC [button]

This would probably mean storing each new unique release group id in a file as the Matching CDs display is loaded then working through them loading any releases that are both (1) not in the Matching CDs list and (2) have the right number of tracks.

If there are no "Same release group" entries to show then do not display the headings or Attach CD-TOC button.