How can I set Cycles samples per View Layer?

It might be something totally obvious that I’m missing, but how can I set sampling per View Layer in Cycles / Blender 2.80? In earlier versions there was a Property in the Render Layer section that allowed to specify an amount of samples to use for this specific layer. Somehow I am unable to find this in 2.80, not even in Python.

Same goes for Material override.

These options are not available yet in 2.8.

Are they planned for the 2.80 Release? Or are they dependent on the Override System, which (I think) will come at a later stage?