I don't like them scattered all over the place and prefer not to alter Album Artist.
I think you should reconsider the highlighted part of that quote.
If you haven't, you should read about Album Artist and
Album Artist and Album Artist (auto), and
Multiple Artist Albums. There are a lot of other good articles in the Wiki and Forum on related topics. Use the Advanced Search, or if you want better search capability, use the custom Google Search on the
Support page.
MC uses a very similar, but slightly different paradigm to many other audio applications.
The [Artist] field is a List type field, and can hold a semi-colon ";" delimited list of Artists.
The [Album Artist] field is what its name suggests it should be; One Artist who is the primary Artist for the Album. In true compilation Albums, the Album Artist should be "Multiple Artists", which MC handles automatically, unless you override that functionality for a particular Album.
MC then introduces the [Album Artist (auto)] field that looks at the [Artist] and [Album Artist] fields, decides which value holds primary Artist name, and stores that value. If the Album is a true compilation Album, MC sets this field to "(Multiple Artists)". This is a primary key for many searches, Views, and other functionality in MC.
I see from the first image in
this post that you are using the notation of "feat." to add Artists to the list of Artists involved in a track (or Album) and you appear to be adding that notation into the [Album Artist] field rather than the [Artist] field. In MC the featured Artists should be listed in the [Artist] field, separated by a semi-colon as above, and a single Artist should be entered in the [Album Artist] field, when there is more than one Artist in the [Artist] field but you want one Artist to be primary for an Album. This then allows MC to search on all Artists involved in a track, individually, rather than search on a combination of Artists. Using the "feat." notation limits MC's search capabilities.
Anyway, back to what you are trying to achieve in your use of MC, assuming you are willing to change the way you use the [Album Artist] field, I would then ask;
What is your underlying intent of creating and using a "Grouping" as you have described? I know you have selected a solution to your needs, based on your use of the [Album Artist] field, but I ask that you think clearly about the reasons you decided on that solution, and hence the underlying intent of it.
If your intent is to be able to find all tracks that a particular Artist is involved in, and show all Tracks in all Albums for any matches, then MC can do that. Just search on the [Artist] you are interested in, and then have MC expand the View to include the full Albums. Refer to the "Modifiers" section of the
Search Language Wiki page, and read about ~a and ~expand. It probably wouldn't hurt to become familiar with the other MC languages in the
Developer Zone in the Wiki as well. You seem capable of understanding all of that.
So implementing your required intent could still be done in more than one way, in Standard View or Theatre View, but the simple thing you would ask MC to do is "Find all tracks with Eric Clapton as an Artist, then expand the View to include full albums." I am not saying that is exactly what you are after, as you need to work out your underlying intent, but it could be as simple as that.
Or it could be more complex, such as "Find all tracks with Eric Clapton as an Artist, then show me who else he has collaborated with, let me select one or more, then expand the View to include full albums."
I think you could do that using a Panes View in MC's Standard View, with two Artist selections, such that once Eric Clapton is selected, MC would build a list of all other Artists involved with his tracks, allow you to select a second or multiple Artists, and then display full Albums that match that criteria. You would be getting into stuff like the Listbuild function in the
Expression Language to do that.
https://wiki.jriver.com/index.php/List_Manipulation_Functions#ListBuildNow I'm not saying that the last example is possible because I haven't tried it. I don't have suitable data in my test Library to test it anyway at the moment. I just think that using the [Album Artist] field to store information such as "Marshmello feat. Somebody" is tying one hand behind your back and making life more difficult for yourself.
PS: Yes, this probably means that you have a bunch of work to do cleaning up existing tags in files, moving featured Artists from the [Album Artist] field to the [Artist] field, and so on. MC has a bunch of tools to help with that process, once you work out exactly what you want to do, and how you want to do it.
TL;DR You are using the [Album Artist] field wrong.