A Virtual Repository defined in Artifactory aggregates packages from both local and remote repositories.
This allows you to access both locally hosted NuGet packages and remote proxied NuGet libraries from a single URL defined for the virtual repository.
To create a virtual NuGet repository, in the Administration module, under Repositories | Repositories | Virtual, click New Virtual Repository and set NuGet to be its Package Type. Select the underlying local and remote NuGet repositories to include under the Repositories section.