How to open a second window from within a window and send data to or from it?

I have an EditorWindow for automating some stuff and speed up workflow in the editor. Something like this:

Code (CSharp):

1. public partial class MyInspector : EditorWindow
2. {
3.     [MenuItem("My Editors/My Inspector _I", false, 0)]
4.     public static void ShowWindow()
5.     {
6.         // Opens the window, otherwise focuses it if it’s already open.
7.         var window = GetWindow<MyInspector>();
8.         // Adds a title to the window.
9.         window.titleContent = new GUIContent("My Inspector");
10.         // Sets a minimum size to the window.
11.         window.minSize = new Vector2(250, 50);
12.     }
13.  
14.     public void OnEnable()
15.     {
16.         VisualTreeAsset visualTree = AssetDatabase.LoadAssetAtPath<VisualTreeAsset>("Assets/Editor/MyInspector.uxml");
17.         VisualElement ui = visualTree.Instantiate();
18.         rootVisualElement.Add(ui);
19.  
20.         StyleSheet styleSheet = AssetDatabase.LoadAssetAtPath<StyleSheet>("Assets/Editor/MyInspector.uss");
21.         rootVisualElement.styleSheets.Add(styleSheet);
22.  
23.         // more code . . .
24.     }
25. }

But I would like to be able to open more windows for specific purposes from pressing a button or something like that. So how do I make a button open a new window, and how can I send objects or values to this new window, and then get objects or values back from it again to the main window?

Example:
I would like to be able to press a button to open a new window and search/filter out specific component that are children of a specific GameObject and create buttons for each result. So I need to send the parent object to the window when it opens and then when I press one of the result buttons it should send that child object back to the main window and assign it there as a reference. Unity of course already has this feature for ObjectFields, but I want to make my own window so that I can customise it more and add other specific features.

 

Any ideas or input on this question?

 

@jonathanma_unity or @cpalma-unity do you have any input on this question?