turns out Visibility works exactly like you'd want for a TreeView

Author: zadjii-msft

src/cascadia/TerminalApp/TasksPaneContent.h

@@ -117,7 +117,7 @@ namespace winrt::TerminalApp::implementation
         // FilteredCommand() = default;
         // FilteredCommand(const winrt::TerminalApp::PaletteItem& item);
 
-        void UpdateFilter(const winrt::hstring& filter) override 
+        void UpdateFilter(const winrt::hstring& filter) override
         {
             TerminalApp::implementation::FilteredCommand::UpdateFilter(filter);
             for (const auto& c : _children)
@@ -150,9 +150,15 @@ namespace winrt::TerminalApp::implementation
         };
         winrt::Windows::Foundation::Collections::IObservableVector<TerminalApp::FilteredTask> Children() { return _children; }
 
+        winrt::Windows::UI::Xaml::Visibility Visibility()
+        {
+            return (_Filter.empty() || _Weight > 0) ? winrt::Windows::UI::Xaml::Visibility::Visible : winrt::Windows::UI::Xaml::Visibility::Collapsed;
+        };
+
     private:
         winrt::Microsoft::Terminal::Settings::Model::Command _command{ nullptr };
         winrt::Windows::Foundation::Collections::IObservableVector<TerminalApp::FilteredTask> _children{ nullptr };
+
     };
 }
 

src/cascadia/TerminalApp/TasksPaneContent.xaml

@@ -33,7 +33,8 @@
             <DataTemplate x:Key="TaskItemTemplate"
                           x:DataType="local:FilteredTask">
                 <mux:TreeViewItem x:Name="rootItem"
-                                  ItemsSource="{x:Bind Children}">
+                                  ItemsSource="{x:Bind Children}"
+                                  Visibility="{x:Bind Visibility}">
                     <Grid>
                         <Grid.RowDefinitions>
                             <RowDefinition Height="*" />

src/cascadia/TerminalApp/TerminalPaneContent.idl

@@ -43,6 +43,7 @@ namespace TerminalApp
     {
         String Input{ get; };
         Windows.Foundation.Collections.IObservableVector<FilteredTask> Children { get; };
+        Windows.UI.Xaml.Visibility Visibility { get; };
     }
 
     [default_interface] runtimeclass TasksPaneContent : Windows.UI.Xaml.Controls.UserControl, IPaneContent