Can we assign multiple objects like leads, contacts to same lookup?

Hello Nagaraju,

You can create a multi-lookup in the same way as it is created in an out-of-the-box version of the application for "Customer" field on an opportunity edit page (here is the screenshot of this field http://prntscr.com/p5ns1j) and achieve your business task in such a way. The code example can be found in OpportunityPageV2 (in Opportunity package) http://prntscr.com/p5nto6. Please analyze it and create the same logic for needed field.

Best regards,

Oscar