HI,
take a look here:
http://scn.sap.com/docs/DOC-42435
and here :
Mapping BEx Query Elements to SAP BusinessObjects BI4 Query Panel
Also keep in mind that Web Intelligence is a reporting tool and not an analytical tool and that Web Intelligence will always struggle with BW as data source and that you should look at the Analysis clients.
regards
Ingo Hilgefort