diff --git a/docs/layouts/sub-navigation.md b/docs/layouts/sub-navigation.md
index 4b6a930a..3a52533b 100644
--- a/docs/layouts/sub-navigation.md
+++ b/docs/layouts/sub-navigation.md
@@ -19,4 +19,8 @@ title: Page title
 Page content
 ```
 
-Use [common front matter options](/layouts#common-front-matter-options) to customise which items and content appear within a page.
+In addition to [common front matter options](/layouts#common-front-matter-options), this layout also accepts the following options:
+
+| Name           | Type   | Description                                                                                                                                                |
+| :------------- | :----- | :--------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| **sectionKey** | string | Parent navigation key (usually a page title) to show items below in the sub navigation. Default is `homeKey` value provided in [plugin options](/options). |
diff --git a/layouts/sub-navigation.njk b/layouts/sub-navigation.njk
index 39f8962d..5fd2567b 100644
--- a/layouts/sub-navigation.njk
+++ b/layouts/sub-navigation.njk
@@ -11,7 +11,7 @@
   <div class="govuk-grid-row">
     <div class="govuk-grid-column-one-quarter-from-desktop">
       {{ xGovukSubNavigation({
-        items: collections.ordered | eleventyNavigation(options.homeKey) | itemsFromNavigation(page.url, { pathPrefix: options.pathPrefix })
+        items: collections.ordered | eleventyNavigation(sectionKey or options.homeKey) | itemsFromNavigation(page.url, { pathPrefix: options.pathPrefix })
       }) }}
     </div>
     <div class="govuk-grid-column-three-quarters-from-desktop">