Swiftui Dynamic CloudKIt predicate - dynamic

Question

I am trying to make a dynamic predicate for Cloudkit to return items that match the segmented picker control. so for example
let predicate = NSPredicate(format: "department == %#", "Marketing") the 'marketing' part of the predicate would be a String variable which changes depending on the segmented picker control. I have tried #State #Published but none work. I have Googled Cloudkit dynamic predicates but there is little out there. Any help would be gratefully received.
This is my code
class staffCloudKitViewModel: ObservableObject {
#Published var text: String = ""
#Published var staff: [StaffModel] = []
#Published var predicateString: String = ""
init(){
fetchItems()
UISegmentedControl.appearance().selectedSegmentTintColor = UIColor(red: 116/255,
green: 152/255, blue: 192/255, alpha: 1.0)
UISegmentedControl.appearance().setTitleTextAttributes([.foregroundColor:
UIColor.white], for: .selected)
}
func fetchItems() {
//let predicate = NSPredicate(value: true)
let predicate = NSPredicate(format: "department == %#", "Marketing")
let query = CKQuery(recordType: "Staff", predicate: predicate)
query.sortDescriptors = [NSSortDescriptor(key: "lastName", ascending: true)]
let queryOperation = CKQueryOperation(query: query)
var returnedItems: [StaffModel] = []
queryOperation.recordMatchedBlock = { (returnedRecordID, returnedResult) in
switch returnedResult {
case .success(let record):
guard let firstName = record["firstName"] as? String else { return }
guard let lastName = record["lastName"] as? String else { return }
guard let department = record["department"] as? String else { return }
guard let country = record["country"] as? String else { return }
guard let mobile = record["phone"] as? String else { return }
guard let job = record["job"] as? String else { return }
let imageAsset = record["headshot"] as? CKAsset
let imageURL = imageAsset?.fileURL
returnedItems.append(StaffModel(firstName: firstName, lastName: lastName,
country: country, department: department, phoneNumber: mobile, job: job,
headshot:
imageURL, record: record))
case .failure(let error):
print("Error recordMatchedBlock: \(error)")
}
}
queryOperation.queryResultBlock = { [weak self] returnedResult in
print("RETURNED RESULT \(returnedResult)")
DispatchQueue.main.async {
self?.staff = returnedItems
}
}
addOperation(opertaion: queryOperation)
}
func addOperation(opertaion: CKDatabaseOperation) {
CKContainer.default().publicCloudDatabase.add(opertaion)
}
}
struct ContentView: View {
#State private var countryselected: Country = .UK
#StateObject private var vm = staffCloudKitViewModel()
var body: some View {
NavigationView {
VStack {
Picker("Select country", selection: $countryselected) {
ForEach(Country.allCases, id: \.self){
Text($0.rawValue)
}
}
.pickerStyle(SegmentedPickerStyle())
.padding()
List {
ForEach(vm.staff, id: \.self) { thepeople in
VStack (alignment: .leading) {