Update content/en/docs/concepts/content-placement/placement.md

Co-authored-by: Mike Ng <[email protected]>

Author: haoqing0110

content/en/docs/concepts/content-placement/placement.md

@@ -60,6 +60,8 @@ sets in the hub clusters. Then we can move on and create a placement in the
 
 ### Predicates
 
+In the `predicates` section, you can select clusters by labels, [clusterClaims](../cluster-inventory/clusterclaim), or CEL expressions. 
+
 #### Label or ClusterClaim Selection
 
 In the `predicates` section, you can select clusters by labels, [clusterClaims](../cluster-inventory/clusterclaim), or CEL expressions.