Hi Mohit,
you cannot create Business Layer from an OLAP connection. All the connections needs to be relation connections to have the multisource universe in IDT.
You can only use multi-source universes on relational data, not OLAP and relational
Please refer the below also.
IDT: multisource universe with function module and BEx query?
Note:
Please see this tutorial on multi-source universes
http://scn.sap.com/docs/DOC-22055
Also, I recommend you to post this in the Semantic Layer space at for quicker responce