Create an array of Struct arrays? - arrays

Question

I have a query that builds a Struct array from some objects. I want to append multiple of these structs into a single array so that i can use it populate a collectionview that is nested inside a collectionview. Im not sure this is the best idea but its all I've got a the moment.
So my Struct is:
struct CollectionStruct {
var name : String
var description : String
var title : String
var image : PFFile
var id: String
}
In my viewcontroller the variable to hold the struct is thus:
var packArray : [CollectionStruct] = []
var partArray : [CollectionStruct] = []
var packId = ""
So below what I'm doing is using an item of the previously created packArray to query the DB and build my partArray. Because i want to do this multiple times and append the partArray into a larger parent array i was thinking of using a for loop like:
var i = 0
for item in self.packArray as [AnyObject] {
self.packId = self.packArray[i].id
BuildArray.buildArrayFromQuery(queryForCollection: "Part", selectedPackID: self.packId, delegateSender: "DownloadPart", completeBlock: { (result) in
self.partArray = result
// append this to an array of partArray????
})
}
I don't even know where to start with this. Is it a bad idea?
essentially what i thought was to call this parent array in cellforitem maybe something like:
innerCell.imageCell.image = parentArray[indexPath.item].partArray[indexPath.item].image
but i could be way off.
----- EDIT -----
so i can use a multidimensional array inside the closure once self.partArray is set:
self.partArray = result
var parentArray = [[self.partArray]]
parentArray.append([self.partArray])
but this is unusable outside the closure. How to declare this multidimensional array before self.partArray is set?
------- EDIT -------
Looking into globals for this at the moment.
class GlobalPartArray {
private init() { }
static let sharedInstance = GlobalPartArray()
var globalPartArray = [CollectionStruct]()
}
class GlobalParentArray {
private init() { }
static let sharedInstance = GlobalParentArray()
var globalParentArray = [[GlobalPartArray]]()
}
then inside closure:
GlobalPartArray.sharedInstance.globalPartArray = result
//can not convert [CollectionStruct] to [GlobalPartArray]
GlobalParentArray.sharedInstance.globalParentArray.append(GlobalPartArray.sharedInstance.globalPartArray)
but it throws an error when trying to convert. I obviously need to convert this data somehow before appending to the GlobalParentArray.