This achievement is unlocked after completing the Forest Maze puzzle in chapter 6. It unlocked for me after the cutscene at Borgavirki when I gain control of Senua to walk inside the settlement.
To complete the maze, always stick to your right path whenever there's a choice otherwise choose the only path forward.
Extended Timestamps:
00:00:00 - Intro & Recap
00:06:00 - Chapter One - Reykjanestá
00:11:00 - Landfall
00:15:45 - "Worth a Thousand Words" Achievement
00:16:45 - 01/18 Lorestangir
00:22:05 - Shore of Slaves
00:26:15 - Capsized Ship
00:31:10 - Slavemaster Found
00:37:00 - "The Next Sign" Achievement
00:37:10 - Chapter Two - Freyslaug
00:38:20 - Freyslaug Sighted
00:39:00 - 02/18 Lorestangir
00:46:15 - Settlement Entrance
00:49:50 - Return Home
00:55:25 - 03/18 Lorestangir
00:56:40 - 01/17 Hidden Face
00:59:20 - Draugar Ceremony
01:04:35 - 04/18 Lorestangir
01:08:40 - Draugar Battle
01:11:35 - Meeting the Stranger
01:13:55 - "The Man in the Middle" Achievement
01:14:30 - 02/17 Hidden Face
01:16:45 - 05/18 Lorestangir
01:21:20 - Chapter Three - Rauðhólar
01:22:00 - Red Hill
01:22:45 - 03/17 Hidden Face
01:24:10 - 04/17 Hidden Face
01:25:20 - 06/18 Lorestangir
01:28:00 - Illtauga
01:32:20 - On the Hill
01:44:00 - Find the Hiddenfolk
01:47:55 - 07/18 Lorestangir
01:50:15 - 05/17 Hidden Face
01:53:00 - 06/17 Hidden Face
01:54:20 - 08/18 Lorestangir
01:59:15 - 07/17 Hidden Face
02:00:25 - 09/18 Lorestangir
02:01:40 - 10/18 Lorestangir
02:05:05 - 11/18 Lorestangir
02:10:40 - Chapter Four - Huldufólk
02:11:15 - "The Hidden World" Achievement
02:11:40 - Enter the Caves
02:12:55 - 08/17 Hidden Face
02:14:35 - 12/18 Lorestangir
02:16:45 - 09/17 Hidden Face
02:18:25 - 10/17 Hidden Face
02:22:45 - 13/18 Lorestangir
02:30:55 - Trial of Wisdom
02:37:25 - Into Darkness
02:43:20 - Act of Sacrifice
02:49:10 - 11/17 Hidden Face
02:50:35 - 14/18 Lorestangir
02:57:15 - Breaking Through
03:05:15 - A Gift Returned
03:15:20 - The First Ritual
03:24:55 - Chapter Five - Bárðarvik
03:25:30 - To The Sea
03:26:25 - "Returned to the Earth" Achievement
03:27:25 - 12/17 Hidden Face
03:28:40 - 15/18 Lorestangir
03:30:25 - Sjávarrisi
03:35:00 - 13/17 Hidden Face
03:39:00 - 16/18 Lorestangir
03:47:10 - 14/17 Hidden Face
03:49:00 - Another Question
03:53:05 - 17/18 Lorestangir
03:54:40 - 15/17 Hidden Face
04:05:25 - 16/17 Hidden Face
04:06:55 - 18/18 Lorestangir
04:07:30 - "Tales of Midgard" Achievement
04:08:10 - 17/17 Hidden Face
04:08:25 - "Glimpses of the Gods" Achievement
04:10:00 - Ástriðr’s Story
04:22:50 - Waking the Giant
04:24:40 - The Second Ritual
04:37:50 - Chapter Six - Borgarvirki
04:38:45 - Into the Forest
04:38:50 - "The Storm Calmed" Achievement
04:52:30 - Borgarvirki
04:55:00 - "A Guiding Light" Achievement
04:58:30 - Heart of Darkness
05:14:50 - The Last Lie
04:23:15 - Ending
04:27:45 - "End the Tyranny" Achievement
04:28:15 - "Seeing Things Differently" Achievement
05:28:50 - Subscribe!