diff -up include/services.inc.php.orig include/services.inc.php
--- include/services.inc.php.orig	2019-08-05 12:07:21.981394637 +0200
+++ include/services.inc.php	2019-08-05 13:38:21.993073536 +0200
@@ -142,6 +142,11 @@ function createServiceConfigurationTree(
 	}
 }
 
+function startsWith($haystack, $needle) {
+     $length = strlen($needle);
+     return (substr($haystack, 0, $length) === $needle);
+}
+
 /**
  * Creates nodes that can be used to display the SLA report tree using the CTree class.
  *
@@ -189,6 +194,18 @@ function createServiceMonitoringTree(arr
 	}
 	// create a not from the given service
 	else {
+		$username = CWebUser::$data['alias'];
+
+		if (startsWith($username,'cust-') && startsWith($service['name'],'cust-')) {
+			$username_customer = explode('-',$username)[1];
+			$node_customer = explode('-',$service['name'])[1];
+			if ($username_customer !== $node_customer) return;
+		}
+
 		$serviceSla = $slaData[$service['serviceid']];
 		$slaValues = reset($serviceSla['sla']);