Analogs for FindWindow, SetParent and MoveWindow WinAPI functions in iPadOS and macOS

Question

I have a Windows OS application that runs as 2 separate processes. processA has its own window, and processB also has its own window which is binded inside window of processA with usage of WinAPI calls.

I am going to rewrite this application for iOS, and to do so, I should replace 3 main steps which use WinAPI calls:

1. When processA started, it searches for the processB window via call to FindWindow: https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-findwindowa

2. When window of process is successfully found, it is binded inside processA window via call to SetParent: https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-setparent

3. When parent changed, position/size of processB window can be changed by calls to MoveWindow: https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-movewindow

The main question is - does iPadOS or macOS provide some similar API to manipulate windows of different processes?

For now I did not find API that I can use for such purposes with C/C++