CinematicController.cs

using UnityEngine;
using UnityEngine.Playables;
using System.Collections;
using System.Collections.Generic;

public class CinematicController : MonoBehaviour {
    public PlayableDirector director;
    public bool IsPaused { get => director.state == PlayState.Paused; }

    public GameObject[] controlables;
    

    public void Play () {
        director.Play();
    }

    public void TogglePause () {
        if (IsPaused) {
            director.Resume();
        } else {
            director.Pause();
        }
    }

    public void Stop () {
        director.Stop();
    }
}

CinematicControllerEditor.cs

using UnityEngine;
using UnityEditor;
using UnityEditor.SceneManagement;

[CustomEditor(typeof(CinematicController))]
public class CinematicControllerEditor : Editor {
    CinematicController Target { get => (CinematicController) target; }
    public static bool isEditingGoal = false;
    public static Tool lastTool;

    void OnEnable () {
        lastTool = Tools.current;
        Tools.current = Tool.None;
        Debug.Log("enable!");
    }

    void OnDisable () {
        Tools.current = lastTool;
        Debug.Log("disable!");
    }

    // https://docs.unity3d.com/ScriptReference/EditorGUILayout.html
    // https://docs.unity3d.com/ScriptReference/GUILayout.html
    public override void OnInspectorGUI () {
        DrawDefaultInspector();
        if (Target.director == null) return;

        if (GUILayout.Button("Play")) {
            Target.Play();
        }

        if (GUILayout.Button(Target.IsPaused? "Resume": "Play")) {
            Target.TogglePause();
        }

        isEditingGoal = GUILayout.Toggle(isEditingGoal, "Mover goal", "Button");

        if (GUI.changed && !Application.isPlaying) {
            EditorUtility.SetDirty(Target);
            EditorSceneManager.MarkSceneDirty(Target.gameObject.scene);
        }
    }

    // https://docs.unity3d.com/ScriptReference/Gizmos.html
    // https://docs.unity3d.com/ScriptReference/Handles.html
    // https://docs.unity3d.com/ScriptReference/IMGUI.Controls.BoxBoundsHandle.html
    public static void DrawGizmos (CinematicController target) {
        Tools.current = Tool.None;
        if (isEditingGoal) {
            foreach (GameObject controlable in target.controlables) {
                controlable.transform.position =
                    Handles.PositionHandle(controlable.transform.position, Quaternion.identity);
            }
        }
    }

    void OnSceneGUI () {
        DrawGizmos(Target);

        if (GUI.changed && !Application.isPlaying) {
            EditorUtility.SetDirty(Target);
            EditorSceneManager.MarkSceneDirty(Target.gameObject.scene);
        }
    }
}