Hi,
Welcome to the WT CJ4. Like many of us there would be a fair amount of reading to get familiar with its systems.
It’s Flight Management system offers various flavors of input. Direct, Import from SimBrief or Import from MSFS.
The White LNV1 has a function and meaning as well. And the NAV function works perfectly well including PT, User Waypoints, charts integration etc.
You can check out the details with WT CJ4 Guides document here:
And also check out the YT Video Tutorial here: MSFS 2020 | TUTORIAL: How to fly the Working Title Cessna Citation CJ4 | Complete Lesson - YouTube
And also their invaluable Discord Channel