The term for parasitoids that attack other parasitoids is a "hyperparasitoid". I did my PhD on parasitoids that attack aphids, but I've never heard of a hyper-hyperparasitoid, do you have any reference to that example?
I was under the impression that it’s fairly common?
The caterpillar: Often a pest species like the tomato leafminer
Primary parasitoid: Cotesia glomerata
Secondary parasitoid: Lysibia nana and some species from the genus Gelis like agilis
Tertiary parasitoid: Certain species within the Trichogramma or Eulophidae families.
I recently discovered the existence of hyperparasitoid wasps much to the delight of my entomologist friend. That these things fly and have working nervous system (apparently ditching the neuronal nuclei during metamorphosis?), the ability to navigate etc. continues to blow my mind. They are so tiny!