Navigation Groups: Specifying Multiple Groups in a Single Document

We find the Navigation Groups function extremely useful for producing lists of pages relating to specific groups. Readers can scan down a long list of pages related to a particular group looking for something of interest. For example we have a Nav Group for 1939, one for 1940 etc. Readers are finding our lists very useful

https://aircrewremembered.com/lists-to-explore.html

We create a list for a particular Group by specifying that Group in the Navigation Group region defined for that page.

What we want to do is now create a composite list bringing together the content from 1939, 1940, 1941 etc without creating a new Group 1939-1945 and going back through our pages re-tagging them all with the new Group.

I tried putting '1939, 1940, 1941, 1942 etc' in the Nav Group for the new composite page but unsurprisingly this naive effort failed.

Is there a way to do what we want?