Info expersion in y2y sync data stream impex

Hi All, I am working on y2y sync data replication from Hybris to SAP.I have checked the OOTB y2ysyncdemoelectronics extension.In that there is stream configuration impex ,I have need clarification on info expression. 2)I have requirement like 2 item types A and B. A-to B have 1 to many relation.Now i want to get the A item type details based on B pk number.Now how can i configure query under where class column and how can i pass parameters for that query in impex.

INSERT_UPDATE Y2YStreamConfiguration; streamId[unique = true]; container(id); itemTypeForStream(code); whereClause; versionSelectClause; catalogVersion(catalog(id), version); infoExpression[default = '']; dataHubType; excludedTypes(code)

; classAttributeAssignmentStream ; y2ySyncDemoElectronicsToDataHub ; ClassAttributeAssignment ; {classificationClass} IN ({{SELECT {cc.PK} FROM {ClassificationClass AS cc} WHERE {cc.catalogVersion}=?catalogVersion}}) ; ; ElectronicsClassification:1.0 ; "%deleteViaRaw%classificationClass->#{getClassificationAttribute().getCode()}:#{getClassificationAttribute().getSystemVersion().getCatalog().getId()}:#{getClassificationAttribute().getSystemVersion().getVersion()}|classificationAttribute->#{getClassificationClass().getCode()}:#{getClassificationClass().getCatalogVersion().getCatalog().getId()}:#{getClassificationClass().getCatalogVersion().getVersion()}|systemVersion->#{getSystemVersion().getCatalog().getId()}:#{getSystemVersion().getVersion()}" ; ClassAttributeAssignmentRaw ;