Add new buttons to LayoutPanel header that has look and feel of pin and close buttons

Hello,
These default buttons are drawn using our internal theme-dependent resources. As a possible solution, you can try using our DockPaneControlBoxButton element in the ControlBoxContentTemplate property and put the Path element whose Fill property is bound to DockPaneControlBoxButton's foreground color:

XAML
<dxdo:LayoutPanel.ControlBoxContentTemplate>
    <DataTemplate>
        <ve:DockPaneControlBoxButton>
            <Path
                Width="16"
                Height="16"
                Stretch="Fill"
                Fill="{Binding Path=(TextElement.Foreground), RelativeSource={RelativeSource Self}}"
                Data="F1 M 319.344,237.333L 287.328,218.849L 287.328,255.818L 319.344,237.333 Z "/>
        </ve:DockPaneControlBoxButton>
    </DataTemplate>
</dxdo:LayoutPanel.ControlBoxContentTemplate>

I've attached a simple sample demonstrating the main idea of this approach.
However please note, this element is a part of our themes' internal structure and may be changed in future. Thus, I recommend that you use another way to display such a button. You can find how these buttons are drawn in our themes using techniques described in the following article: How to find and change an inner DevExpress control template. After that, create you own templates for your buttons which are based on these theme-dependent templates. Although this approach is more time-consuming, it's more safe than using this inner element.

Thanks,
Kirill