How to properly bind CommandParameter in grouped CollectionView , Xamarin forms?

I have created a grouped collection view in Xamarin Forms. The collection view has 2 buttons(1 label with tap gesture recognition), one in the collection view Header and another in the body.

<CollectionView IsGrouped="True" ItemsSource="{Binding Items}">
                <CollectionView.GroupHeaderTemplate>
                    <DataTemplate>
                        <ContentView Padding="0,10,0,0">
                            <Grid
                                BackgroundColor="Black"
                                ColumnDefinitions="*,30"
                                HorizontalOptions="FillAndExpand">
                                <Label
                                    HorizontalOptions="Start"
                                    Text="{Binding Title}"
                                    TextColor="White" />
                                <Label
                                    BackgroundColor="BLue"
                                    FontAttributes="Bold"
                                    HorizontalOptions="End"
                                    HorizontalTextAlignment="Center"
                                    Text=">"
                                    TextColor="White"
                                    WidthRequest="30">
                                    <Label.GestureRecognizers>
                                        <TapGestureRecognizer Command="{Binding BindingContext.ToggleForm, Source={Reference thisPage}}" CommandParameter="{Binding .}" />
                                    </Label.GestureRecognizers>
                                </Label>

                            </Grid>
                        </ContentView>
                    </DataTemplate>
                </CollectionView.GroupHeaderTemplate>
                <CollectionView.ItemTemplate>
                    <DataTemplate>
                        <StackLayout BackgroundColor="Azure" IsVisible="{Binding IsVisible}">
                            <Label Text="{Binding Description}" />
                            <Button
                                Padding="0"
                                BackgroundColor="Blue"
                                Command="{Binding BindingContext.BodyButtonCommand, Source={Reference thisPage}}"
                                CommandParameter="{Binding .}"
                                HeightRequest="30"
                                HorizontalOptions="Start"
                                Text="Click"
                                TextColor="white"
                                VerticalOptions="Start" />

                        </StackLayout>
                    </DataTemplate>
                </CollectionView.ItemTemplate>
            </CollectionView>

Here is the View Model for this

public class GroupedItemsTestViewModel
    {
        public ObservableCollection<GroupedItem> Items { get; set; }
        public ICommand ToggleForm { get; }
        public ICommand BodyButtonCommand { get; }
        public GroupedItemsTestViewModel()
        {
            Items = new ObservableCollection<GroupedItem>()
            {
              new GroupedItem("Title 1",new List<Details>{ new Details() {Description="Description 1" } }),
              new GroupedItem("Title 2",new List<Details>{ new Details() {Description="Description 2" } }),
              new GroupedItem("Title 3",new List<Details>{ new Details() {Description="Description 3" } })
            };
            ToggleForm = new Command(toggleFormVisibility);
            BodyButtonCommand = new Command(changeBody);
        }

        private void toggleFormVisibility(object obj)
        {
            var type = obj.GetType();
            var clickedObj = obj as GroupedItem;
            if (clickedObj != null)
            {
                var form = clickedObj.Form;
                form.IsVisible = form.IsVisible==true?false:true;
            }

        }
        private void changeBody(object obj)
        {
            var clickedObj = obj as GroupedItem;
        }
    }

On clicking the label(in the header) to toggle the form(body of the collection view) visibility, the GroupedItem is passed as the object in the toggleFormVisibility(object obj) function parameter.
But On clicking the Button in the Body of the collection view the object passed is only the Details object.

Here is the GroupedItem implementation:

public class GroupedItem : List<Details>
    {
        public string Title { get; }
        public Details Form { get; }
        public GroupedItem(string title, List<Details> form) : base(form) 
        {
            Title = title;
            Form = form[0];
        }
    }

How can I get the GroupedItem as the passed object on clicking the Button in the body just like on clicking the label in the Header?

> How can I get the GroupedItem as the passed object on clicking the Button in the body just like on clicking the label in the Header?

You can put the Button into GroupFooterTemplate like this:

<CollectionView IsGrouped="True" ItemsSource="{Binding Items}">
            <CollectionView.GroupHeaderTemplate >
                ....
            </CollectionView.GroupHeaderTemplate>

            <CollectionView.ItemTemplate>
                <DataTemplate>
                    <StackLayout BackgroundColor="Azure" IsVisible="{Binding IsVisible}">
                        <Label Text="{Binding Description}" />
                        <!--<Button
                                Padding="0"
                                BackgroundColor="Blue"
                                Command="{Binding BindingContext.BodyButtonCommand, Source={Reference thisPage}}"
                                CommandParameter="{Binding .}"
                                HeightRequest="30"
                                HorizontalOptions="Start"
                                Text="Click"
                                TextColor="white"
                                VerticalOptions="Start" />-->
                   </StackLayout>
                </DataTemplate>
            </CollectionView.ItemTemplate>

            <CollectionView.GroupFooterTemplate>
                <DataTemplate>
                    <StackLayout >
                        <Button
                                Padding="0"
                                BackgroundColor="Blue"
                                Command="{Binding BindingContext.BodyButtonCommand, Source={Reference thisPage}}"
                                CommandParameter="{Binding .}"
                                HeightRequest="30"
                                HorizontalOptions="Start"
                                Text="Click"
                                TextColor="white"
                                VerticalOptions="Start" />
                   </StackLayout>
                </DataTemplate>
            </CollectionView.GroupFooterTemplate>
</CollectionView>

So you can get the GroupedItem as the passed object on clicking the Button. And this is the effect:

Update:

As Ashish said, in addition to the above method to get GroupedItem through GroupFooterTemplate, there is another way to achieve it:

> By making only one from item(collection view body) to be visible at a time. Now I just send the GroupedItem that is visible when I click the Button. Since the visibility is handled by the arrow in the header and hence I can get the whole grouped item.