diff --git a/src/AdvancedCalculator/Views/MainView.axaml b/src/AdvancedCalculator/Views/MainView.axaml
index 5bb4dff..7beff7c 100644
--- a/src/AdvancedCalculator/Views/MainView.axaml
+++ b/src/AdvancedCalculator/Views/MainView.axaml
@@ -37,10 +37,15 @@
             <ListBox.ItemTemplate>
               <DataTemplate x:DataType="m:VariableItem">
                 <Button Background="Transparent" BorderThickness="0" Padding="8" MinHeight="44"
+                        x:DataType="{x:Null}"
                         AutomationProperties.Name="Insert variable"
-                        Command="{Binding DataContext.InsertVariableCommand, RelativeSource={RelativeSource AncestorType=UserControl}}"
-                        CommandParameter="{Binding VariableName}">
-                  <Grid ColumnDefinitions="Auto,*,Auto">
+                        Tag="{Binding}"
+                        DataContext="{Binding $parent[UserControl].DataContext}"
+                        Command="{Binding InsertVariableCommand}"
+                        CommandParameter="{Binding Tag.VariableName, RelativeSource={RelativeSource Self}}">
+                  <Grid ColumnDefinitions="Auto,*,Auto"
+                        DataContext="{Binding Tag, RelativeSource={RelativeSource AncestorType=Button}}"
+                        x:DataType="m:VariableItem">
                     <TextBlock Grid.Column="0" FontFamily="{StaticResource MDI}"
                                FontSize="{DynamicResource IconSizeM}" Text="{Binding Icon}" VerticalAlignment="Center" Margin="0,0,8,0" />
                     <TextBlock Grid.Column="1" Text="{Binding VariableName}" FontWeight="Bold" VerticalAlignment="Center" />
@@ -67,10 +72,15 @@
           <ListBox.ItemTemplate>
               <DataTemplate x:DataType="m:FunctionDefinitionItem">
                 <Button Background="Transparent" BorderThickness="0" Padding="8" MinHeight="44"
+                        x:DataType="{x:Null}"
                         AutomationProperties.Name="Insert function"
-                        Command="{Binding DataContext.InsertFunctionCommand, RelativeSource={RelativeSource AncestorType=UserControl}}"
-                        CommandParameter="{Binding FunctionName}">
-                  <StackPanel Spacing="8">
+                        Tag="{Binding}"
+                        DataContext="{Binding $parent[UserControl].DataContext}"
+                        Command="{Binding InsertFunctionCommand}"
+                        CommandParameter="{Binding Tag.FunctionName, RelativeSource={RelativeSource Self}}">
+                  <StackPanel Spacing="8"
+                              DataContext="{Binding Tag, RelativeSource={RelativeSource AncestorType=Button}}"
+                              x:DataType="m:FunctionDefinitionItem">
                     <StackPanel Orientation="Horizontal" Spacing="8" VerticalAlignment="Center">
                       <TextBlock FontFamily="{StaticResource MDI}" Text="{Binding Icon}" />
                       <TextBlock Text="{Binding FunctionName}" FontWeight="Bold" />