There is a per-world chat feature, kind of. it uses permissions and can be enabled in config (useChatPermissions):
https://wiki.traincarts.net/p/MyWorlds/Permissions
Basically, grant players the myworlds.world.chat.world1.world2 perm then players messages in world2 are visible in world1 (I think). Not sure how well they work though, it's an old feature.
Tablist Ive avoided because a lot of plugins mess with this - and myworlds messing with it too can cause a lot of incompatibilities. I'd suggest trying to find a plugin dedicated to making the tablist chat filtered to a specific (set of) worlds, if that exists.