How to add packageSourceMapping targeting pattern and version in NuGet.Config

In an C# based project, I am using preview packages are are hosting on a nuget.cloudsmith.io not nuget.org. The production packages are hosted on nuget.org.

I want to define rules in my Nuget.config file to restore preview packages from nuget.cloudsmith.io but others from nuget.org

So any package id that starts with PackagePrefix. and the version contains -preview- should be downloaded from cloudsmith.io. Any other package should be downloaded from nuget.org.

For example, the package PackagePrefix.SomeProject with version 2.5.0 will be downloaded from nuget.org. But, The package PackagePrefix.SomeOtherProject with version 2.6.0-preview-5 will be downloaded from cloudsmith.io.

Here is what I have done. But I can't find a way to target package-id + version pattern. I tried to map using <package pattern="PackagePrefix.*" version="*-preview-*" /> but this does not seems to be working.

<?xml version="1.0" encoding="utf-8"?><configuration><packageSources><clear /><add key="nuget.org" value="https://api.nuget.org/v3/index.json" /><add key="cloudsmith.io" value="https://nuget.cloudsmith.io/PackagePrefix/preview/v3/index.json" /></packageSources><packageSourceMapping><!-- key value for <packageSource> should match key values from <packageSources> element --><packageSource key="nuget.org"><package pattern="*" /></packageSource><packageSource key="cloudsmith.io"><package pattern="PackagePrefix.*" version="*-preview-*" /></packageSource></packageSourceMapping></configuration>

Here is the warning I get when trying to build a project

warning NU1507: There are 2 package sources defined in your configuration. When using central package management, please map your package sources with package source mapping (https://aka.ms/nuget-package-source-mapping) or specify a single package source. The following sources are defined: nuget.org, cloudsmith.io

How can I map a package using package id and package version to a specific source?