I'm not sure what you mean by a tab named Campaign Setting for 5e, unless its something done by Kobold Press in their stuff (I don't own those items, so can't say).
What some of us do that have "heavily modified" files is we set up a source that is related to our campaigns. We then use the editor to preclude, append and extend things in our .user files and make sure to associate these campaign specific changes to our source.
For example, my home Greyhawk campaign source precludes any of the languages, backgrounds, class options, deities and equipment that I've precluded as being non-Greyhawk. Those options don't show up when I've got the Greyhawk source selected. There are even some automated ways of doing this, which were discussed in
this thread.
So, making a new source and .1st file aren't too difficult. You can look at these files using notepad or your favorite text editor, as the COMmunity files have a lot of examples.