I suppose the simplest would be to have to split to two windows with the same buffer with "Ctrl x 3", and press "Shift+Tab" to only have the headline. That is if all the conversation are on the same file.

If they are not on the same file, maybe something simple like deft (https://github.com/jrblevin/deft) or more complex like org-roam (https://github.com/org-roam/org-roam)