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NSPredicate for nested relationships

I'm having trouble formatting a predicate to find nested relationships in master data. I came across some very similar questions / comments that I hoped would help me find the right solution, but I was still stuck.

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I am trying to create a select query to search for all Foo instances associated with a specific gadget instance.

First I tried using the predicate for fetchRequest for the Foo object:

[NSPredicate predicateWithFormat:@"ANY bar.widgets.gadget == %@", myGadget]

but this fetch query returns 0 results. I guess it is because of the relationship nested to many.

I think I need to use a subquery that I have never had to use before. After much research and reading, I tried

 [NSPredicate predicateWithFormat:@"SUBQUERY(bar.widgets, $w, ANY $w.gadget == %@) .@count > 0", myGadget]

And I get an error

SQLite error code: 1, "no such column: t2.ZGADGET"

So, I correctly understood that I need a subquery for this scenario, and if so, how to format it correctly?

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