What I mean is editing the same file parallel in two windows/tabs – changes in one area become visible in the other one immediately.
That feature was available some years ago, but I never needed it. Now I would need it for some C++ code editing, but can not manage to get it working. Google does not really help.
Would be sad if it should have been removed – it is supported by GTK-Source-View, I hacked it into my plain Nim editor some years ago. Just tested, works fine still. But that editor was customized to Nim language, it is unuseable for C++. (https://github.com/StefanSalewski/NEd)