Displaying Different Collections in Viewports in the Same Workspace

I'm trying to port my Blender Light Studio plugin to Blender 2.8 but currently there is a big feature missing (demo is below to clearly show what I mean): leomoon.com/downloads/plugins/blender-light-studio/

In 2.7x we had the small dots for layers. So we could display some layers in one 3D view and some other layers in another 3D view at the same time.

How do we display different collections in viewports in the same workspace in 2.80?

Thanks.