Running ReSharper Tests in Parallel by NameSpace

I am wondering if I can run my NUnit tests in parallel, I'm using the R# test runner and there is the option of running assemblies in parallel.

I have a Test Project with all of the tests and they are all 'grouped' and ordered by namespace. Is there any ability to be able to run tests in namespaces in parallel? Example of what I mean by 'grouping'