ToggleSelection "globally"

I’ve been looking at the Exploring example, and playing around with the select features it uses.

Below iterates over items displaying the Card class for each and is selectable. However, how could I trigger the ToggleSelection from a panel outside of the loop - the ToggleSelection from within the “Outside” Panel can’t find the selection to toggle. I assume TargetNode could be the answer here, but I haven’t been able to. If that is the solution, what would the correct target be in below? Thx!

<Page>

<DockPanel>

<Panel ux:Name="Outside">
<Clicked>
<ToggleSelection Mode="RemoveOnly" />
</Cicked>
</Panel>

<ScrollView ux:Name="mainScrollView" ClipToBounds="false" LayoutMode="PreserveVisual">
<Panel>
<Selection MinCount="0" MaxCount="1" />
<Each Items="{items}">
<Card>
<Selectable Value="{id}" />
<WhileSelected>
<Change mainScrollView.UserScroll="false" DelayBack="0" />
</WhileSelected>
</Card>
</Each>
</Panel>
</ScrollView>

</DockPanel>

<StackPanel ux:InnerClass="Card" >

<WhileSelected>
</WhileSelected>

<Panel ux:Name="imageAndContent" Alignment="Top">
<Clicked>
<ToggleSelection Mode="AddOnly" />
</Clicked>

<Rectangle CornerRadius="5" Color="Purple" Width="100%" Height="100" />
</Panel>

</StackPanel>

</Page>

It arguably only makes sense for “a thing” to be Selectable, and so ToggleSelection belongs inside of one.

What it is that you are trying to create, which requires you to toggle selection from outside of the items?