Multiple categories for nunit through testfixture and test attributes

[TestFixture(Category = "P1")]
public class TestClass 
{
    [Test(Category = "P2")]
    public void Method()
    {
        //test
    }
}

In the above code snippet, what will be considered the TestCategory of Method : "P1" or "P2" or both?

I want to use the category to filter out the tests.