Maintenance for the week of November 18:
• PC/Mac: No maintenance – November 18
• ESO Store and Account System for maintenance – November 19, 9:00AM EST (14:00 UTC) - 6:00PM EST (23:00 UTC)
• PlayStation®: EU megaserver for maintenance – November 19, 23:00 UTC (6:00PM EST) - November 20, 17:00 UTC (12:00PM EST) https://forums.elderscrollsonline.com/en/discussion/668861
Why can't I see the leaderboards or my friends in ESO PS4
I believe this to be a bug/glitch that is being fixed at the moment, if you are wanting to group up with your friends you could try going to menu - social - group - invite player and then enter in their PSN ID and hopefully this will then allow you to see them.
Another method you could try would be to exit the game and try restarting it, hopefully this will work for you but I do know that a patch is coming out which will hopefully fix this soon.