In Kyma 7, each Timeline track is in its own namespace to protect against accidental collisions of memory names and controller names.
However, in this case, you want to share the same chunk of memory across tracks. You can do this by going to each track that should share the memory; rightClick (Ctrl+Click) on the track name to bring up the track menu; select Sharing Memory Writers: ON.
In this way, you can share memory among specific tracks, without having to make the memory global to all the tracks.