At the start of Chapter 2 in Resident Evil 4 Remake, you can purchase the Treasure Map from the Merchant for 3 Spinels who can be found to the right when you exit the Abandoned Factory. This will display all the treasure locations on the map for the entire village section including Chapter 4 as well as give you a small progression counter in the bottom right corner of the map. Although this will show you their general location, it won’t show you how to get them. Read below how to get all seven treasures in Chapter 4.
Treasure: 1 - Ruby
Once you begin Chapter 4, work your way around the Mural Cave until you come across another docked boat, then you’ll want to use it and follow the stream along to the left until you reach the dock to the Large Cave Shrine. Here you’ll and to follow the path around until it splits into two, then climb up the ladder on the right to find a container hanging to the left of the wooden bridge. Shoot it and drop to retrieve the Ruby.
Treasure: 2 - Alexandrite
Return to the boat and drive over to the shipwreck in the center of the lake where you’ll find a chest that contains the Alexandrite.
Treasure: 3 - Red9 Pistol
Go over to the front of the ship and open the blue chest for the Red9 Pistol.
Treasure: 4 - Velvet Blue
Hop back on the boat and drive over to the island on the east side of the lake. Here you’ll find the Velvet Blue sitting on top of a wooden barrel in the corner on the left side. Additionally, here is where you can get the Gold Chicken Egg for the Egg Hunt Request.
Treasure: 5 - Pearl Bangle
Return to the boat and take a trip up to the Lakeside Settlement which is located in the northwest corner. Here you’ll want to walk along the narrow path to the left of the building to the find a Wayshrine that’ll require you to use the Old Wayshrine Key in order to open so you can retrieve the Pearl Bangle. If you missed the key you can find out how to get it via this page: Where to Find the Old Wayshrine Key in Resident Evil 4 Remake
Treasure: 6 - Gold Bar
Remain on the Lakeside Settlement and go up to the Forest Altar and collect the Small Key from the cart, then enter the large house and open the chester drawers on the left to obtain the Gold Bar.
Treasure: 7 - Red Gemstone Ring
Follow the corridors around in the house until you find the hatch leading to the basement, then drop down and follow the path around to find the Red Gemstone Ring sitting on top of a white box.