Hm, wouldn't just ".." be more familiar looking?

I was going along the lines of func(t ...T), if I saw .. I would thing up in the hierarchy not down

But this isn't about varargs. If it needs to be any amount of dots, I believe a single . makes most sense since you are accessing a member of the struct, going down one level in the hierarchy, which is exactly what it looks like elsewhere in the language.

A different idea: add another tag-field. Kinda how for json we may write json:",omitempty" we could write sql:",recurse".