It is planned to include something even more powerful then the currently very limited local ratsnest view:
from bug report Comment #3 : Bug #1740156 : Bugs : KiCad
The ‘show local ratsnest’ tool has rather limited usability. For the next development cycle (post-5.0) we plan to have per-net, per-netclass and per-component rat line visibility control. Also it will be possible to change the net colors.