You need to add the Agreement Hierarchy button on the Agreement Detail page to view the agreement hierarchy.
To add the Agreement Hierarchy button
- Go to Setup > Build > Create > Objects.
- In the Custom Objects page, click the Agreement hyperlink.
- Navigate to the Page Layouts section and click the Edit hyperlink for Agreement Layout.
From the Buttons category in the palette, drag Agreement Hierarchy (New) into the Custom Buttons section of the Agreement Detail.
- Click Save.