效果：

先在菜单栏里面找到Tools/CheckPrefabLayers打开窗口

代码：

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

public class CheckPrefabLayers : EditorWindow
{
    public int selectedLayerIndex = 0;

    void OnGUI()
    {
        string[] layerNames = UnityEditorInternal.InternalEditorUtility.layers;
        selectedLayerIndex = EditorGUILayout.Popup("检查层级:", selectedLayerIndex, layerNames);
        if (GUILayout.Button("开始查找"))
        {
            CheckLayers();
        }
    }
    private void CheckLayers()
    {
        // 指定资源文件夹路径
        string folderPath = "Assets/Prefab";

        // 获取指定文件夹下所有预制体的路径
        string[] prefabPaths = Directory.GetFiles(folderPath, "*.prefab", SearchOption.AllDirectories);
        

        foreach (string prefabPath in prefabPaths)
        {
            // 加载预制体
            GameObject prefab = AssetDatabase.LoadAssetAtPath<GameObject>(prefabPath);

            // 检查预制体的 Layer 层级
            if (prefab != null && prefab.layer ==selectedLayerIndex)
            {
                Debug.Log($"Prefab {prefab.name} 在 {prefabPath} 有指定的层级");
            }
        }

        Debug.LogWarning("检测完毕");
    }

    [MenuItem("Tools/Check Prefab Layers")]
    static void Init()
    {
        // 创建窗口实例并显示
        CheckPrefabLayers window = (CheckPrefabLayers)EditorWindow.GetWindow(typeof(CheckPrefabLayers));
        window.Show();
    }
}