<Canvas Name="CanvasContainer">

        <!-- 
        the tooltip requires a canvas to move properly, 
        so lets wrap our view where you need a shared tooltip 
        with a Canvas container
        -->

        <lvc:DefaultTooltip Name="CurrentTooltip" Visibility="Hidden" 
                            Panel.ZIndex="100"
                            Canvas.Left="0" Canvas.Top="0"
                            IsWrapped="True">
            <!--
            it needs to: 
            1. Have an initial position
            2. Be hidden on startup
            3. to be wrapped in a Canvas, and say it with IsWrapped = true
            -->
        </lvc:DefaultTooltip>

        <Grid Height="{Binding ActualHeight, ElementName=CanvasContainer}" 
              Width="{Binding ActualWidth, ElementName=CanvasContainer}">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*"></ColumnDefinition>
                <ColumnDefinition Width="*"></ColumnDefinition>
                <ColumnDefinition Width="*"></ColumnDefinition>
            </Grid.ColumnDefinitions>

            <lvc:CartesianChart Grid.Column="0" Background="White"
                            DataTooltip="{Binding ElementName=CurrentTooltip}">
                <lvc:CartesianChart.Series>
                    <lvc:LineSeries Values="1,2,3,4,5" LabelPoint="{Binding LabelPoint}"></lvc:LineSeries>
                </lvc:CartesianChart.Series>
            </lvc:CartesianChart>
            <lvc:CartesianChart Grid.Column="1" Background="White"
                            DataTooltip="{Binding ElementName=CurrentTooltip}">
                <lvc:CartesianChart.Series>
                    <lvc:LineSeries Values="1,2,3,4,5" LabelPoint="{Binding LabelPoint}"></lvc:LineSeries>
                </lvc:CartesianChart.Series>
            </lvc:CartesianChart>
            <lvc:CartesianChart Grid.Column="2" Background="White"
                            DataTooltip="{Binding ElementName=CurrentTooltip}">
                <lvc:CartesianChart.Series>
                    <lvc:LineSeries Values="1,2,3,4,5" LabelPoint="{Binding LabelPoint}" ></lvc:LineSeries>
                </lvc:CartesianChart.Series>
            </lvc:CartesianChart>
        </Grid>
    </Canvas>