where is viewport unlink in blender 2.8 --- to make window witch created by (duplicated area in to new windows feature) in specific 3d view editor with specific setting.... unlinked from other windows or workspace so the view setting will not change when you open another windows or workspace ... this was possible in blender 2.7 ... it called (viewport unlink).
In my case I had two characters on different layers in Blender 2.79 and I used unlink viewport to see them both on the screen at the same time.
In Blender 2.82 there is no unlink viewport button, but since I had the characters in separate layers they were imported in as separate collections.
If you go to you workspace and select the View tab on the right side, then select collections at the bottom, you can then use local collection. Then you can hide the other collections you are not using. This will allow you to manipulate each character in their own workspace.