i’m trying to add a MultiBinding on my DataTrigger but without succeed.

here’s the code of my DataGridTextColumn :

<DataGridTextColumn Binding="{Binding Flex_01}" SortMemberPath="Flex_01" Header="Flex 01" Width="60" ElementStyle="{StaticResource WrapText}" HeaderTemplate="{StaticResource HeaderTemplate}" IsReadOnly="True">
   <DataGridTextColumn.CellStyle>
      <Style TargetType="{x:Type DataGridCell}" BasedOn="{StaticResource Common_style}">
         <Style.Triggers>
            <DataTrigger Binding="{Binding Flex_01_Flag}" Value="True">
               <Setter Property="Background">
                  <Setter.Value>
                     SolidColorBrush Color="DodgerBlue" Opacity="0.5"/>
                  </Setter.Value>
               </Setter>
               <Setter Property="ToolTip">
                  <Setter.Value>
                    <ToolTip>
                       <ToolTip.Content>
                          <MultiBinding Converter="{StaticResource Daily_Comparison}" ConverterParameter="ToolTip">
                             <MultiBinding.Bindings>
                                <Binding />
                                <Binding Path="PlacementTarget" RelativeSource="{RelativeSource Self}"/>
                             </MultiBinding.Bindings>
                           </MultiBinding>
                        </ToolTip.Content>
                    </ToolTip>
                 </Setter.Value>
               </Setter>
            </DataTrigger>
         </Style.Triggers>
      </Style>
  </DataGridTextColumn.CellStyle>
</DataGridTextColumn>

i want to user the same converter i have in the ToolTip, and send another ConverterParameter to be able to choose in my converter what to send back.

i want to convert this to the same way i did with the ToolTip:

<DataTrigger Binding="{Binding Flex_01_Flag}" Value="True">
   <Setter Property="Background">
      <Setter.Value>
         SolidColorBrush Color="DodgerBlue" Opacity="0.5"/>
      </Setter.Value>
   </Setter>

Thank you for your help