I cannot identify what you are looking for, but perhaps this will start you off along the right track.


DECLARE @data XML = N'<navigation>
<content label="Introduction">
<content label="Intro" id="000286_1001"/>
</content>
<content label="Premature Atrial Contractions">
<content label="Description" id="000286_1002"/>
<content label="ECG Features" id="000286_1003"/>
<content label="Etiology/Symptoms/Treatment" id="000286_1004"/>
</content>
<content label="Wandering">
<content label="Description" id="000286_1005"/>
<content label="ECG Features" id="000286_1006"/>
<content label="Etiology/Symptoms/Treatment" id="000286_1007"/>
</content>
<content label="Ectopic Atrial Rhythm">
<content label="Description" id="000286_1008"/>
<content label="ECG Features" id="000286_1009"/>
<content label="Etiology/Symptoms/Treatment" id="000286_1010"/>
<content label="Supraventricular Tachycardia">
  <content label="SVT" id="000286_1011"/>
  <content label="Etiology/Symptoms/Treatment" id="000286_1012"/>
</content>
<content label="Multifocal Atrial Tachycardia">
  <content label="Description" id="000286_1013"/>
  <content label="ECG Features" id="000286_1014"/>
  <content label="Etiology/Symptoms/Treatment" id="000286_1015"/>
</content>
<content label="Ectopic Atrial Tachycardia">
  <content label="Description" id="000286_1016"/>
  <content label="ECG Features" id="000286_1017"/>
  <content label="Etiology/Symptoms/Treatment" id="000286_1018"/>
</content>
<content label="Ectopic Atrial Tachycardia with Block">
  <content label="Description" id="000286_1019"/>
</content>
<content label="Atrial Flutter">
  <content label="Description" id="000286_1020"/>
  <content label="ECG Features" id="000286_1021"/>
  <content label="Etiology/Symptoms/Treatment" id="000286_1022"/>
  <content label="Treatment" id="000286_1023"/>
</content>
<content label="Atrial Fibrillation">
  <content label="Description" id="000286_1024"/>
  <content label="ECG Features" id="000286_1025"/>
  <content label="Etiology/Symptoms/Treatment" id="000286_1026"/>
  <content label="Signs" id="000286_1027"/>
  <content label="Treatment" id="000286_1028"/>
</content>
<content label="AVRT">
  <content label="Description" id="000286_1029"/>
  <content label="Pathophysiology" id="000286_1030"/>
  <content label="ECG Features" id="000286_1031"/>
  <content label="Etiology" id="000286_1032"/>
</content>
<content label="AVNRT">
  <content label="Description" id="000286_1033"/>
  <content label="ECG Features" id="000286_1034"/>
  <content label="Etiology" id="000286_1035"/>
</content>
<content label="Treatment" id="000286_1036"/>
</content>
<content label="Review">
<content label="Quick Quiz" id="000286_1037"/>
</content>
<content label="Conclusion">
<content label="Summary" id="000286_1038"/>
</content>
</navigation> ';

SELECT
  NavigationId = ROW_NUMBER() OVER (ORDER BY ISNULL(C.c.value('@id', 'VARCHAR(50)'), '999999_999')
               , ISNULL(G.r.value('@id', 'VARCHAR(50)'), '999999_999'))
, [Type] = T.l.value('@label', 'VARCHAR(100)')
, Parent_label = C.c.value('@label', 'VARCHAR(100)')
, Parent_id = C.c.value('@id', 'VARCHAR(50)')
, Child_label = G.r.value('@label', 'VARCHAR(100)')
, Child_id = G.r.value('@id', 'VARCHAR(50)')
FROM @data.nodes('navigation/content') AS T(l)
CROSS APPLY T.l.nodes('content') AS C(c)
OUTER APPLY C.c.nodes('content') AS G(r);