MainPage.xaml

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:vm="clr-namespace:MauiApp1"
             x:Class="MauiApp1.MainPage"
             x:DataType="{x:Type vm:ViewModel}">

    <VerticalStackLayout>
        <Button Text="Select using Binding" Command="{Binding PreSelectUsingBindingCommand}" />
        <CollectionView x:Name="collectionView"
                        ItemsSource="{Binding Items}"
                        SelectionMode="Multiple"
                        SelectedItems="{Binding SelectedItems, Mode=TwoWay}">
            <CollectionView.ItemTemplate>
                <DataTemplate>
                    <Label Text="{Binding .}" FontSize="Small" Margin="10"/>
                </DataTemplate>
            </CollectionView.ItemTemplate>
        </CollectionView>
    </VerticalStackLayout>

</ContentPage>