AFAIK, Nested layouts templates structure is not supported by Hugo.
this structure is not supported:
layouts/products/random/list.html
layouts/products/random/single.html
The only way is by setting the type
to random
in the frontmatter of products/random/dummy.md
.
So https://example.com/products/random/
will use layout template from layouts/random/{list, single}.html
References: