Example code :

select top 1 name from DIRPARTYTABLE
inner join HcmWorker ON HcmWorker.PERSON = DIRPARTYTABLE.RECID
AND HcmWorker.RECID = 
	(select top 1 worker from HCMPOSITIONWORKERASSIGNMENT  
	INNER JOIN HCMPOSITION ON HCMPOSITIONWORKERASSIGNMENT.POSITION =  HCMPOSITION.RECID
	AND HCMPOSITION.RECID = 
		(select TOP 1 ParentPosition from  hcmPositionHierarchy 
			INNER JOIN  hcmPositionHierarchyType on hcmPositionHierarchy.PositionHierarchyType = hcmPositionHierarchyType.RECID AND hcmPositionHierarchyType.HierarchyType = 0
			where hcmPositionHierarchy.Position = 
				(select top 1 POSITION from HCMPOSITIONWORKERASSIGNMENT  
				INNER JOIN HCMPOSITION ON HCMPOSITIONWORKERASSIGNMENT.POSITION =  HCMPOSITION.RECID
				where GETDATE() between HCMPOSITIONWORKERASSIGNMENT.VALIDFROM AND HCMPOSITIONWORKERASSIGNMENT.VALIDTO 
				AND HCMPOSITIONWORKERASSIGNMENT.WORKER = 
					(select TOP 1 WORKER from hcmEmployment where hcmEmployment.RECID = 5637152077)))
	where GETDATE() between HCMPOSITIONWORKERASSIGNMENT.VALIDFROM AND HCMPOSITIONWORKERASSIGNMENT.VALIDTO);