IQL to get a subset of linked objects

[Linda Milne_Togetha Group_]

I have a set of linked objects in Insight, the essential components are:

ObjectType1

   Name1

   Attr1  linked to ObjectType2

ObjectType2

   Name2

   Attr2 linked to ObjectType3

ObjectType3

   Name3

I want to get a list of the ObjectType3 objects that are not linked in ObjectType2 via ObjectType1. Can I get a list of the objects ObjectType1.Attr1.Attr2 and then remove them from the list of ObjectType3 objects?

Is anything like this possible with IQL, or am I going to have to look at something like groovy / scriptrunner? And if the latter, is that even possible, because Im not sure how to return a list of objects in a way that I can display them?