Few questions about Unity3D and Google Play Leaderboards

Im starting work with the google play services, specifically with the leaderboards.
I did everything according to the tutorials, but i still have a few questions.

Social.localUser.Authenticate(authenticated =>
            {
                if (!authenticated || !Social.localUser.authenticated)
                {
                    throw new System.Exception();
                }
                
                Social.ReportScore((long) (GameObject.FindGameObjectWithTag("Disp").GetComponent<timer>().tmp * 1000), level_key, (bool success) =>
                {
                    if (success)
                    {
                        Social.ShowLeaderboardUI();
                    }
                    else
                    {
                        throw new System.Exception();
                    }
                });
            });
  1. Is there a way to show player not all leaderboards, but the leaderboard of current level?
  2. By default leaderboards shows results between friends, can i easily switch it to global?

1)YES
If you wish to show a particular leaderboard instead of all leaderboards, you can pass a leaderboard ID to the method. This, however, is a Play Games extension, so the Social.Active object needs to be cast to a PlayGamesPlatform object first:

using GooglePlayGames;
using UnityEngine.SocialPlatforms;
...
// show leaderboard UI
PlayGamesPlatform.Instance.ShowLeaderboardUI("Cfji293fjsie_QA");

2)Yes there is options in leaderboard to switch to global