When in 2D mode, is there a way to specify that a polyline/billboard should appear above a KML/CZML layer?
I don’t think this functionality is available for a polyline, but you can use the Billboard.eyeOffset to make the billboard draw in front of other primitives. Giving it a negative Z value should make it appear above other layers.
For a polyline, I think the best work-around right now would be to give all the points a small height above the other layer.
Thank your for this information. I was able to get part of the desired behavior (billboard above polyline) with the eye offset option for billboards.