how files are nested below other files in a .csproj

Open a .csproj file in notepad to example the underlying XML...

   <ItemGroup>
      <Content Include="Web.Debug.config">
         <DependentUpon>Web.config</DependentUpon>
      </Content>
   </ItemGroup>
   <ItemGroup>
      <Content Include="Web.PROD.config">
         <DependentUpon>Web.config</DependentUpon>
      </Content>
   </ItemGroup>
   <ItemGroup>
      <Content Include="Web.DIT.config">
         <DependentUpon>Web.config</DependentUpon>
      </Content>
   </ItemGroup>
   <ItemGroup>
      <Content Include="Web.SIT.config">
         <DependentUpon>Web.config</DependentUpon>
      </Content>
   </ItemGroup>