an example here ..
http://dev.day.com/docs/en/cq/current/developing/developing-reports.html#Creating%20Your%20Own%20Report%20-%20An%20Example
the example has outlined cq widgetscollection(nodes*) to define the query limiting the nodetype ( to see the last line ..P:nodeTypes [String[]] = "sling:OsgiConfig")
N:items [cq:WidgetCollection]
N:props [cq:Panel]
N:items [cq:WidgetCollection]
N:title [cq:Widget]
P:path [String] = "/libs/cq/reporting/components/commons/title.infinity.json"
P:xtype [String] = "cqinclude"
N:description [cq:Widget]
P:path [String] = "/libs/cq/reporting/components/commons/description.infinity.json"
P:xtype [String] = "cqinclude"
N:rootPath [cq:Widget]
P:fieldLabel [String] = "Root path"
P:name [String] = "./report/rootPath"
P:xtype [String] = "pathfield"
N:processing [cq:Widget]
P:path [String] = "/libs/cq/reporting/components/commons/processing.infinity.json"
P:xtype [String] = "cqinclude"
N:scheduling [cq:Widget]
P:path [String] = "/libs/cq/reporting/components/commons/scheduling.infinity.json"
P:xtype [String] = "cqinclude"
N:queryBuilder [nt:unstructured]
P:nodeTypes [String[]] = "sling:OsgiConfig"
-Venu Gummadala