ソースコード

using System.Linq;
using UnityEditor;
using UnityEngine;

public class Example
{
    [MenuItem( "Tools/Hoge" )]
    private static void Hoge()
    {
        var list = Selection
            .GetFiltered<UnityEngine.Object>( SelectionMode.Assets | SelectionMode.DeepAssets )
            .Select( x => AssetDatabase.GetAssetPath( x ) )
            .SelectMany( x => AssetDatabase.GetDependencies( x ) )
            .Where( x => !x.EndsWith( ".cs" ) )
            .Distinct()
            .OrderBy( x => x )
            .ToArray()
            ;

        var result = string.Join( "\n", list );

        EditorGUIUtility.systemCopyBuffer = result;
        Debug.Log( result );
    }
}