class ViewModel {
    private var isSelectedBehaviorRelay = BehaviorRelay<Bool>(value: false)

    lazy var isSelectedObservable: Observable<Bool> = {
        isSelectedBehaviorRelay.asObservable()
    }()

    init(_ isSelected: Bool) {
        isSelectedBehaviorRelay.accept(isSelected)
    }
}

class SomeOtherViewModel {
    private var viewModelsBehaviorRelay = BehaviorRelay<[ViewModel]>(value: [
        ViewModel(true),
        ViewModel(false),
        ViewModel(true),
        ViewModel(false),
        ViewModel(true)
        ])
    private let disposeBag = DisposeBag()

    lazy var filteredViewModelsObservable: Observable<[ViewModel]> = {
        viewModelsBehaviorRelay
            .flatMapLatest { viewModels in
                Observable.from(viewModels)
                    .flatMapLatest { viewModel in
                        viewModel.isSelectedObservable
                            .take(1)
                            .filter { $0 }
                            .map { _ in viewModel } // If true, map event to viewModel that owns the property
                    }
                    .toArray()
            }
    }()
}

let viewModel = SomeOtherViewModel()
viewModel.filteredViewModelsObservable.debug().subscribe(onNext: {
    print($0)
    // The ViewModel objects whos isSelectedObservable property are true
}).disposed(by: disposeBag)