I have merged two Test Group (.jmx) file under one Test Plan and trying to run simultaneously. It's running one after another sequentially which I don't want.

Example: I want to run 2 scenarios at a time (simultaneously) to measure the load but here I am facing problem and it's running the first scenario and then moving to second scenario sequentially.

Please tell me if there will be any setup in Test Plan that I am missing. Waiting for your reply.