Lets say you have two viewControllers, FirstViewController and SecondTableViewController.
Create a segue identifier for embedded segue in your storyboard lets say "SecondTableViewControllerContainerSegue"
class FirstViewController: UIViewController {
private var someValueFromFirstVC = 5
private var childContainerController:SecondTableViewController?
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if (segue.identifier == "SecondTableViewControllerContainerSegue"){
self.childContainerController = segue.destination as? SecondTableViewController
self.childContrainerController.someValueFromSecondVc = someValueFromFirstVC
}
}
}
If your problem is more specific let me know i will update accordingly.