I’m new and I’m completely lost to the difference of the “overview” to the “releases”/“recordings”/“work” menu panes.
The three later show what they should show, they are probably complete.
But which subset is being displayed on the “overview”?
Any help and explanation is appreciated!
What you see in the Overview tab are the release groups.
All editions of an album will be grouped in one release group.
There is even a number of releases (editions) contained in each release group. 
Thanks for your answer.
Perhaps I don’t understand you fully.
The artist who got me into this question is different.
I have the
Christiane Oelze, Hartmut Haenchen, Mozart: Concert Arias, Berlin Classics CD at hand
Christiane Oelze is:
This album neither shows on the “overview” or “release” menu pane.
It is shown on the “recordings” pane, which is a long, detailed and exaustive list.
This CD is part of the “Complete Mozart Works”, CD 6:
and the artist is correctly linked.
So I can find it - but why does the “overview” not show this release group?
Can you see my difficulty?
The “Overview”-Panel is sourced from the Artists included in the Release (and Release Group) Artist field. Unfortunately we have no way to show (in the overview) Releases included in huge boxed sets like this 170CD-“Complete Mozart” (or the 74-CD-“Complete Verdi Operas” I’m dealing with right now… https://musicbrainz.org/release-group/d53a49bb-5037-4f5c-871e-16c73863aab0). If we had just a single album the Aritsts that we now have as Recording Artist ( Christiane Oelze, Kammerorchester Carl Philipp Emanuel Bach, Hartmut Haenchen would most probably be found on the cover art and thus appear as Release Artists – and so also in the Overview. In a 100+ CD-box set, the only Artist appearing as Release Artist will (for practical reasons, with hundreds or thousands of performers involved) be the composer (for Mozart or Verdi boxes) or one single performer (for Callas or Karajan-Boxes). I can’t see how this can be changed 
Thanks for explaining that.
lt’s only been ? 3 years and now I know.
I’m not sure that the current “Overview” is user friendly in total - it appears not new user friendly, it appears not casual user friendly.
Perhaps another, less misleading, name for that field is needed.
Then don’t forget to use both Overview and Relationships tab to (try to) see everything. 