Copy NuGet contentFiles transitively to referenced project

I have a NuGet package in which is an extra file packaged as a Content in contentFiles folder.

Then I have two C# projects with SDK-style .csproj - A and B where Project B references Project A as a ProjectReference and there is a classic PackageReference of a NuGet package in the Project A like this:

NuGet package ← Project A ← Project B

My problem is that the extra file gets correctly copied to the build output of Project A, but it won't get copied to the output of Project B unless I do it manually.

Is there a way how to force copy the extra file from the NuGet dependency transitively to the Project B build output?

The only way I can think of is custom Post-build event with xcopy command but it's more of a workaround than a real solution.

Thanks for any advice in advance!