Here is a more universal expression for calculated measure to get Xray Test Runs by the Component of Test and other fields associated with Test Execution issues and test run results.
Sum(
--filter set of Tests
Filter(
Descendants([Xray Test].CurrentMember,[Xray Test].[Test]),
--Test issue has selected Component
DefaultContext((
[Measures].[Xray Tests created],
[Xray Test].CurrentHierarchyMember,
[Component].CurrentHierarchyMember
)) > 0 ),
--sum up test runs ignoring Component assigned to Test Execution
([Measures].[Xray Test Runs],
[Component].CurrentHierarchy.DefaultMember)
)