You can find more details on how to use Query Builder on Adobe’s web site at https://helpx.adobe.com/experience-manager/6-3/sites/developing/using/querybuilder-api.html.
Your local Query Builder tool can be found at http://localhost:4502/libs/cq/search/content/querydebug.html. Replace “http://localhost:4502” with your appropriate domain and port.
Here are some helpful queries I have used in the past.
Search for LDAP Users
http://localhost:4502/bin/querybuilder.json?1_group.1_property=rep%3aexternalId&1_group.1_property.operation=exists&property=jcr:primaryType&property.value=rep:User&p.hits=selective&p.properties=rep:authorizableId%20rep:fullname&p.limit=-1
Search for LDAP Groups
http://localhost:4502/bin/querybuilder.json?1_group.1_property=rep%3aexternalId&1_group.1_property.operation=exists&property=jcr:primaryType&property.value=rep:Group&p.hits=selective&p.properties=rep:authorizableId%20rep:members&p.limit=-1