The guiding principle of the sitemap is that each node must be unique. Therefore, you cannot have 1 node in 2 different places because the match will always be the first node.
However, you can create 2 different nodes that point to the same resource, each with its own unique route (and unique URL). You just need to ensure there is more than one route that reaches your action. There is a document describing how to do that here: https://github.com/maartenba/MvcSiteMapProvider/wiki/Multiple-Navigation-Paths-to-a-Single-Page
Also, there is a working example on my blog: http://www.shiningtreasures.com/post/2013/08/10/mvcsitemapprovider-4-seo-features#canonical-tag
That just uses the default route with another querystring parameter, but you could also add an additional route to the same controller action in your MVC application to get the same result.