Hi Ashish,
We do not have anything like "transaction type" available in IS-U... that's why you cannot set a filter for BUS_TRANS_MSG. In fact if you would like to filter ISU contacts for example, you should use object SI_BCONTACT. If you would like to filter Sales document from SD (tcode VA01 - VA02 - VA03), you should use object SALESDOCUMENT, etc.
Hope that helps,
Best regards
Nicolas.