FetchRequest based on subset criteria - core-data

Question

Consider the following object graph:
#objcMembers class Event: NSObject {
let name: String
let sections: [Section]
init(name: String, sections: [Section]) {
self.name = name
self.sections = sections
}
}
#objcMembers class Section: NSObject {
let name: String
let videos: [Video]
init(name: String, videos: [Video]) {
self.name = name
self.videos = videos
}
}
#objcMembers class Video: NSObject {
let name: String
let isFavorite: Bool
let isWatched: Bool
init(name: String, isFavorite: Bool, isWatched: Bool) {
self.name = name
self.isFavorite = isFavorite
self.isWatched = isWatched
}
}
I would like to filter the event sections which only have the videos marked as favorites
let events = [Event(name: "2021 Event",
sections: [
Section(name: "Monday",
videos: [Video(name: "VideoMonday1",
isFavorite: true,
isWatched: true),
Video(name: "VideoMonday2",
isFavorite: false,
isWatched: true)]),
Section(name: "Tuesday",
videos: [Video(name: "VideoTuesday1",
isFavorite: false,
isWatched: false),
Video(name: "VideoTuesday2",
isFavorite: true,
isWatched: true)])
])
]
//Expected result
let filtered = [Event(name: "2021 Event",
sections: [
Section(name: "Monday",
videos: [Video(name: "VideoMonday1",
isFavorite: true,
isWatched: true)]),
Section(name: "Tuesday",
videos: [Video(name: "VideoTuesday2",
isFavorite: true,
isWatched: true)])
])
]
Im using CoreData, and i came up with this predicate:
let favPredicate = NSPredicate(format: "SUBQUERY(sections, $sect, SUBQUERY($sect.videos, $vid, $vid.isFavorite == YES).#count > 0).#count > 0")
This however doesnt exclude the videos which are not favorites, from the sections.
It s a query which runs on the event entity, and "it works" because it filters the array, but not what im looking for.
I can achieve this as soon as i get the root array: however, i d like to accomplish this using coreData, by not loading not needed objects in memory. Is this possible or its not worth in terms of complexity?