Double Closing / Simultaneous Closing sales techniques?

[Joshua Shamah]

Hey all, first timer here, working to secure a home under contract, in order to initiate a sale through transactional funding, or a double closing.

What I'm trying to figure out is how to actually find a second buyer? How am I supposed to sell a home I have under contract if I can't exactly walk the next buyer through the home? How do you actually find, and sell a home you have under contract to someone else? 

Do real estate investors go and hire real estate agents to sell a house they don't fully own yet? I feel there's a huge piece of this puzzle missing, from an new investor standpoint.