This is the query example from the OpenCMIS Workbench modified with a query string that shows how to query for properties defined in an Alfresco aspect using a join.

query-aspect.groovy

import org.apache.chemistry.opencmis.commons.*
import org.apache.chemistry.opencmis.commons.data.*
import org.apache.chemistry.opencmis.commons.enums.*
import org.apache.chemistry.opencmis.client.api.*

String cql = "SELECT D.cmis:name, T.cm:title FROM cmis:document as D join cm:titled as T on D.cmis:objectId = T.cmis:objectId"

ItemIterable<QueryResult> results = session.query(cql, false)

results.each { hit ->  
    hit.properties.each { println "${it.queryName}: ${it.firstValue}" }
    println "--------------------------------------"
}

println "--------------------------------------"    
println "Total number: ${results.totalNumItems}"
println "Has more: ${results.hasMoreItems}" 
println "--------------------------------------"