This MSBuild script shows how to filter Items into two separate item lists. This could be used for filtering files for different installers etc .

MsBuildFilter.xml

<?xml version="1.0" encoding="utf-8"?>
<Project
  xmlns="http://schemas.microsoft.com/developer/msbuild/2003"
  ToolsVersion="4.0"
  >
  
  <ItemGroup>
    <Binary Include="SrcDir/assembly01.txt" >
      <Server>.</Server>
    </Binary>
    <Binary Include="SrcDir/assembly02.txt" >
      <Server>.</Server>
      <Desktop>.</Desktop>
    </Binary>
    <Binary Include="SrcDir/assembly03.txt" >
      <Desktop>.</Desktop>
    </Binary>
  </ItemGroup>
  
  <Target Name="Server" >
    <Copy
      DestinationFolder="Server"
      SourceFiles="@(Binary)"
      Condition="%(Binary.Server) != '' "
      />
  </Target>
  
   <Target Name="Desktop" >
    <Copy
      DestinationFolder="Desktop"
      SourceFiles="@(Binary)"
      Condition="%(Binary.Desktop) != '' "
      />
  </Target>  
  
</Project>