The Edit Hierarchy page can be opened from the Manage Hierarchies page of both Detailed and List Views.
To enter the Edit Hierarchy page from the Detailed View you have to click the Edit button below the specific Hierarchy name.
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The Edit Hierarchy page is the same as the Create Hierarchy page. All the fields are editable. Make the needed changes and to save them click the Update Hierarchy button at the footer of the Edit Hierarchy page.
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