Get next child of selected item : HierarchyId

SELECT HierarchyID.GetLevel(),H1.*,(Select CASE WHEN count(1)>1 THEN 1 ELSE 0 END FROM Hierarchies AS H2 WHERE H2.HierarchyID.IsDescendantOf(H1.HierarchyID)=1) AS IsChild
from Hierarchies AS H1
WHERE HierarchyID.GetAncestor(1) = @parentHierarchyId