My desperation about creating Advanced Generic Menu

Lately I started making a game that is complex levels and after one level I fed up. Anyway, what I wanna do is to create a level grid with a button on generic menu. However I also want two textboxes that I can set width and height of my level. Something like this:

Also I want use my generic menu with public functions (In this case public void Init instead of static void Init) eg:

 using UnityEngine;
 using UnityEditor;
 
 public class GenericMenuExample : EditorWindow
 {
     // open the window from the menu item Example -> GUI Color
     [MenuItem("Example/GUI Color")]
    static void Init()
     {
         EditorWindow window = GetWindow<GenericMenuExample>();
         window.position = new Rect(50f, 50f, 200f, 24f);
         window.Show();
     }
 ...

Is there way to do this? Or is there any alternative solutions? Any kind of help appriciated that will help to end my desperation.