Different geometry/materials in different camera viewports

Let’s say I want to draw a map of the world, but I don’t want to use the same high-detail geometry as the regular view, but a stylized version. And also I would like to draw players as StaticMeshes of circles or cubes instead of fully skeletal meshes as they are normally.

Is there a concept of ‘Render groups’ or anything similar that I can use to achieve this ?
If there was, then I could tag certain meshes in the world to show up only in the Map view, while the rest would show up only in the regular view. Ideally they would be checkboxes like in the collision preferences. And inside the class blueprint of the player character, I would have a Skeletal Mesh for the regular, high detail view, and a Box StaticMesh tagged as showing up only in the map view.

How would you implement this in current UE4 ?

EDIT: I see UnrealEd has support for Layers, any way to toggle these for cameras ?