Crossplatform nuget for Android and Windows application

I have a set of three dll files. All files are build with .netstandard2.0

First file is common for Android and Windows, can run on both.

Second and third file consists of the same class, but is platform specific.

One should be used only on Windows targets and second only on Android targets.

I need a nuget that can be used on both: Android and Windows.

In the nuspec file I can use "netstandard", "net" and "monoandroid" abreviations for targerts.

Is there an approach to have a set of files for Android+common and Windows+common dll files?

When I try to set all three categories:

<!-- Common --><file src="Common.dll" target="lib/netstandard2.0/"/><!-- Android --><file src="Android.dll" target="lib/MonoAndroid9.0/"/><!-- .NET Framework --><file src="Windows.dll" target="lib/net472/"/>

it does work on Android, but fails on Windows with the common part dll missing in the project.