Ответ 1
Метаданные предметов - ваш друг!
<Target Name="GetMSBuildProjectParentDirectory">
<!-- First you create the MSBuildProject Parent directory Item -->
<CreateItem Include="$(MSBuildProjectDirectory)\..\">
<Output ItemName="MSBuildProjectParentDirectory" TaskParameter="Include"/>
</CreateItem>
<!-- You can now retrieve its fullpath using Fullpath metadata -->
<Message Text="%(MSBuildProjectParentDirectory.Fullpath)"/>
<!-- Create a property based on parent fullpath-->
<CreateProperty Value="%(MSBuildProjectParentDirectory.Fullpath)">
<Output PropertyName="CodeFolder" TaskParameter="Value"/>
</CreateProperty>
</Target>