Access the iterator value when a list is printed into a document.
In {d[i].cars[i].other.wheels[i].tire.subObject:add(.i):add(..i):add(...i)}
The number of dots equals the number of previous i
:
.i
matches the index value of wheels[i]
..i
matches the index value of cars[i]
...i
matches the index value of d[i]