diff --git a/core/modules/system/src/Plugin/Block/SystemMenuBlock.php b/core/modules/system/src/Plugin/Block/SystemMenuBlock.php
index 83a2f85..00d58e0 100644
--- a/core/modules/system/src/Plugin/Block/SystemMenuBlock.php
+++ b/core/modules/system/src/Plugin/Block/SystemMenuBlock.php
@@ -140,16 +140,31 @@ public function build() {
     $menu_name = $this->getDerivativeId();
     $parameters = $this->menuTree->getCurrentRouteMenuTreeParameters($menu_name);
 
-    // Adjust the menu tree parameters based on the block's configuration.
+    // Get the the block's configuration.
     $level = $this->configuration['level'];
     $depth = $this->configuration['depth'];
-    $parameters->setMinDepth($level);
-    // When the depth is configured to zero, there is no depth limit. When depth
-    // is non-zero, it indicates the number of levels that must be displayed.
-    // Hence this is a relative depth that we must convert to an actual
-    // (absolute) depth, that may never exceed the maximum depth.
-    if ($depth > 0) {
-      $parameters->setMaxDepth(min($level + $depth - 1, $this->menuTree->maxDepth()));
+
+    // Get the active trail.
+    $active_trail = $this->menuActiveTrail->getActiveTrailIds($menu_name);
+
+    if(count($active_trail) < $level) {
+    	// Page is above the menu's starting level. Just hide the menu.
+    	$parameters->setMinDepth($level);
+
+    } else {
+		// Get the root of the menu.
+		$menu_root = array_values($active_trail)[count($active_trail) - $level];
+		// Set the root of the tree.
+		$parameters->setRoot($menu_root);
+		// Set min depth to 1 since the menu tree now starts at the correct root.
+		$parameters->setMinDepth(1);
+		// When the depth is configured to zero, there is no depth limit. When depth
+		// is non-zero, it indicates the number of levels that can be displayed.
+		// With the correct root set, max depth is simply $depth. Make sure it
+		// does not exceed the maxiumum depth allowed.
+		if ($depth > 0) {
+			$parameters->setMaxDepth(min($depth, $this->menuTree->maxDepth()));
+		}
     }
 
     $tree = $this->menuTree->load($menu_name, $parameters);