Custom Game Object Inspector - filter the Inspector to find a property or component, made by Mattimus in the More Mountains Community Discord (updated to work with Unity 2022.3)

CustomGameObjectInspector.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
using System;
using System.Reflection;

[CustomEditor(typeof(GameObject), true)]
[CanEditMultipleObjects]
public class CustomGameObjectInspector : Editor
{
    //Unity's built-in editor
    Editor defaultEditor;
    GameObject gameObject;
    protected string searchText = "";

    void OnEnable()
    {
        //When this inspector is created, also create the built-in inspector
        defaultEditor = Editor.CreateEditor(targets, Type.GetType("UnityEditor.GameObjectInspector, UnityEditor"));
        gameObject = target as GameObject;
        defaultEditor.GetType().GetMethod("OnEnable").Invoke(defaultEditor, null);
    }

    void OnDisable()
    {
        //When OnDisable is called, the default editor we created should be destroyed to avoid memory leakage.
        //Also, make sure to call any required methods like OnDisable
        DestroyImmediate(defaultEditor);
    }

    public override void OnInspectorGUI()
    {
        defaultEditor.OnInspectorGUI();
        defaultEditor.DrawHeader();

        EditorGUI.BeginChangeCheck();
        EditorGUILayout.BeginHorizontal();
        GUI.SetNextControlName("textField");
        EditorGUILayout.LabelField("Find:", GUILayout.Width(50));
        searchText = EditorGUILayout.TextField(searchText);

        //Clear button.
        GUI.SetNextControlName("Button");
        if (GUILayout.Button("X", GUILayout.Width(30)))
        {
            searchText = "";
            GUI.FocusControl("Button");
            SceneView.RepaintAll();
        }
        EditorGUILayout.EndHorizontal();

        if (EditorGUI.EndChangeCheck())
        {
            FilterProperties();
        }
    }

    //filters by property
    void FilterProperties()
    {
        //find all the components on all the game objects
        foreach (var t in targets)
        {
            foreach (Component component in ((GameObject)t).GetComponents<Component>())
            {
                //don't filter out Transform or GameObject.
                if (component.GetType() == typeof(GameObject) || component.GetType() == typeof(Transform))
                {
                    continue;
                }
                
                bool hasProperty = false;

                FieldInfo[] fields = component.GetType().GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);   //get all the fields on this component
                foreach (FieldInfo fI in fields)    //does this component have a field that matches the query
                {
                    if (fI.Name.ToLower().Contains(searchText.ToLower()))
                    {
                        hasProperty = true;
                        break;
                    }
                }

                //hide properties that don't meet the search requirements.
                if (hasProperty || component.GetType().ToString().ToLower().Contains(searchText.ToLower()))
                {
                    component.hideFlags = component.hideFlags & ~HideFlags.HideInInspector;
                }
                else
                {
                    component.hideFlags = component.hideFlags | HideFlags.HideInInspector;
                }
            }
        }

        foreach (var t in targets)
        {
            EditorUtility.SetDirty(t);
        }

        Repaint();
    }
}