I wanted one entry site and one subsite for each year. For each year I wanted two languages but since I didn’t know about the multilingual features of Hugo I did it using a separate subsite for each language/year combination.
For my new site I want one entry site and one subsite for each year, using the built in multilingual features of Hugo for each subsite.
While convenient in some cases, it’s limiting in others (e.g., your project).
If the menus were based on Hugo’s menu system instead of the theme’s approach, there are easier ways to do this instead of building the site three times.
Starting in Relearn 7.1.0 and further expanded in 7.6.0, you can now configure how navigation menus are created. Instead of the default auto generation from your filesystem structure, you can now also use Hugo menus, let the menu auto generate from a certain page down following your filesystem structure (by using the pageRef parameter), and reconfigure menus for each page.
Everything combined together will generate the whole page in one call to hugo server with the desired menu structure.