Reference a Pipe Response from a join value

Hi All, @moe @Chem @tim.young

In the following Pipe API Response I’m looking to extract the value 174 from the response.

I’ve tried referencing it as items.0.field_551_val.val but that isn’t working (also tried items.0.field_551_val and items[0].field_551_val.val)

I can successfully reference the standard fields such as items.0.field_551 and this will correctly return 7oOjD1drB9 value for example.

What is the syntax for referencing this lower level value?

Many thanks, Graham.