But maybe it becomes too complex, if you have visibility per viewport and visibility per viewlayer? And you also have the Collection viewlayer exclude/include option.

@Dalai Felinto (dfelinto), Isn't it the concept of viewlayers to show diffrent subsets of object? So you can deflect what will be renfered from what you see in the viewport. So I think the visibility which is changing all viewports, should be per viewlayer.

As they are called viewlayer now, maybe you wish some sort of visibility per viewlayer?! Otherwise it woulf only be a renderlayer as in Blender 2.79.

After reading the proposal carfully I now have some questions.

Sounds good, maybe you can then add a button somewhere in the viewport for new users (like the aktive camera icon in the top right)?!
@Dalai Felinto (dfelinto): As I understand the prosal, the visibility of objects in viewlayers would then be controlled by the set exclude/dynamic override of collections?

If the / key would work as a toogle wouldn´t it be more effective in case of performance? I don´t know how blender is handling this. Doing an inverse selection operation followed by a hide operation sounds compute intensive, if you have lots of objects in the scene. I work in the automobile industrie where I have 10000+ geometries in blender. In my opinion local view should be with good performance.

@Dalai Felinto (dfelinto), thanks for you answer, I trust your proposal to be useful in every days work. Thanks for you your hard work! Can you implement the search option for hidden/invisible objects in the outliner, or is it a paper cut? In the moment there are only search options for visible, all, active and selected objects.

@Brecht Van Lommel (brecht), thanks for your advice. Will the screen icon in the outliner be available if the proposal in this thread is realized? Would it be hard to implement a search option for hidden/invisible objects in the outliner. In the moment there are only search options for visible, all, active and selected objects?

The local view (isolate selected) feature is very important!
Please make the visibility/local view setting as it is useful! When you have lots of geometry in the scene you often need to just focus on one object.
Make it at least like in Blender 2.79 where hitting the / key sets the object to local view, when you hit the / key you get out of local view. Objects that were hidden in the viewport remain hidden.
In the moment in blender 2.80 you have to unhide everything (alt h) to get out of local view, which ruins the scene configuration.

The same happens when I try to open blender blender-2.80-4503c96a175-win64, Nov 13 2018

In the Screenshot you can see as described above that, I´m in the cone View Layer and the option Render Single Layer is set to on.
But it renders the Cube View Layer not the View Layer that I´m currently in.
If you switch to the Cylinder View Layer with Render Single Layer on it again renders the Cube View Layer if you hit Ctrl+F12.

Try this file. The are three View Layer called after the primitives that are inside.
Hit Render Animation (Ctrl-F12)
In the image editor you can see all three View Layer rendered.
Select the cylinder and move it slightly to the left.
Switch to View Layer Cone and move it also a little bit to the left.
Switch to View Layer Cube and move the cube to the left so that you can see a difference to the old rendering.
While you are in the Cube View Layer switch the option Render Single Layer on.
Switch to the Cone View Layer - here the option Render Single Layer is now also on.
Hit Render Animation (Ctrl-F12)
Not the Cone View Layer where I´m in, but the Cube View Layer is rendered! Why?

Yes I know how it should work. But if you switch to the attached scene scene to the View Layer.001 with the option Render Single Layer on, Blender is rendering not that layer, but the first View Layer because the option is also set there and the first View Layer is only rendered.
So to say it clear. If the option is on it only renders the first renderlayer in the row, whatever View Layer you have currently active in your view and want to render.
It is not possible to render only a special View Layer!
I hope you understand what I mean?

@Clément Foucault: In the build from today blender-2.80.0-git.3c8c1841d72-windows64 the problem still persists.

Brecht, would it be possible to allow parenting by draging and droping mulible objects in the outliner like it is possible to drag and drop multible objects into collections? That would be really great and makes Blender more consistent!

The selection of the primitives works normal as expected in the latest builds. If you click on the same location the selection cycles through every sphere, also in xray view-mode.