navigating the view hierarchy in SwiftUI

I'm attempting to build an app using SwiftUI, and having getting stuck on a few things that I can't figure out how to implement.

The current challenge can be described as follows:
1. I am displaying a 9x9 grid

2. when a user taps one of the 'cell's I want to present an input view that only requires a portion of the screen. (I'm currently picturing it being non-modal, but feel free to convince me it should be otherwise)

3. I want the input view to animate its frame starting from the cell the user taps, and ending being a square in the middle of the screen (either a fixed final size, or a fixed final portion of the smaller screen dimension.. or perhaps an intrinsic size?)

Any/all help appreciated.

here is some UIViewController-based code that implements what I want to do

class ViewController: UIViewController {

    override func loadView() {
        let result = UIView()
        result.backgroundColor = UIColor.blue
        addButton(superView: result, title: "button1", yMultiplier: 0.8)
        addButton(superView: result, title: "button2", yMultiplier: 1.4)
        view = result
    }
   
    func addButton(superView: UIView, title: String, yMultiplier: CGFloat) {
        let button = UIButton()
        button.setTitle(title, for: .normal)
        button.backgroundColor = UIColor.green
        button.addTarget(self, action: #selector(buttonTapped(sender:)), for: .touchUpInside)
        button.translatesAutoresizingMaskIntoConstraints = false
        superView.addSubview(button)
        let centerX = NSLayoutConstraint(item: button, attribute: .centerX, relatedBy: .equal, toItem: superView, attribute: .centerX, multiplier: 1.0, constant: 0)
        let centerY = NSLayoutConstraint(item: button, attribute: .centerY, relatedBy: .equal, toItem: superView, attribute: .centerY, multiplier: yMultiplier, constant: 0)
        superView.addConstraints([centerX, centerY])
    }
   
    @objc func buttonTapped(sender: UIButton) {
        let tempView = UIView(frame: sender.frame)
        tempView.backgroundColor = UIColor.red
        tempView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        tempView.translatesAutoresizingMaskIntoConstraints = true
        view.addSubview(tempView)
        UIView.animate(withDuration: 1.0, animations: {
            tempView.frame.size = CGSize(width: 200, height: 200)
            tempView.center = self.view.center
        }) { (success) in
            tempView.removeFromSuperview()
        }
    }

}