Keep Tabbar when click on central button

Question

I am using following layout design

but when i click on central circular button it's cover the whole screen ... i want to make tabbar visible on every click ...

I try to open ViewController as a sub view with following code

  guard let StoreVC = self.storyboard?.instantiateViewController(withIdentifier: "StoreVC") else { return }
   StoreVC.view.frame = self.view.bounds
   self.addChild(StoreVC)
   self.view.addSubview(StoreVC.view)
   StoreVC.didMove(toParent: self)

but its cover the entire screen including tabbar ..

i try following code but still does't work as expected ...

       guard let StoreVC = self.storyboard?.instantiateViewController(withIdentifier: "StoreVC") else { return }
       self.definesPresentationContext = true
       StoreVC.modalPresentationStyle = .overCurrentContext
       self.present(StoreVC,animated: true, completion: nil)

Embedding it in a navigation controller also does't work ...

This circular button is not the part of Tabbar but i want it to act like a tabBarItem ...

if i make it part of tabbar it upper part not click able ...

just like explain in this question TabBarController adding custom button not clickable issue