BIRT with remedy

hello everyone i am working on BIRT to generate reports on data taken by the Remedy system.
i am stuck at one place and i will explain the situation if any one can help .
i have two data sets one is RCA and other is HPD .
RCA has incident number which is unique and HPD has one field request id2 which is same as Incident number in RCA.Request id 1 has data depending upon the request id2 number. now i want to display request id 1 and for request id2 i have passes a parameter so that it takes up the value from the incident number. but i dont know how to display request id 1 which is dependent on request id 2.
can anyone help ? please reply