The Museum is the third level of Sifu.To unlock the achievement you have to find the 17 collectibles. Some of them are automatically unlocked as you progress through the level. I will list them anyway.
Below is the board collectibles with numbers:
Collectible #1 -
Club Code - You need the Museum Keycard first.
On the third floor, you encounter a female combatant with blue hair. You got this by killing her.
Collectible #2 -
Exhibition: Identity - At the start of the mission and after killing the first 2 guys, take the hallway on the right and collect the pamphlet on the stand before entering the first room
Collectible #3 -
Security - This entry will be added to the board by killing the first two enemies of the level
Collectible #4-
Family Photo - In the room you access by opening the Artist Residence Door (#17). You will need the Artist's Key to open the door (mission The Tower, #14)
Collectible #5-
Museum Map - In the atrium at the beginning of the level, next to the ramp on the right-hand side. You will find a stack of maps
Collectible #6-
Kuroki's Inner Circle - You will encounter these two enemies with glowing feet, in a dark room. This is just before the boss fight
Collectible #7-
Strange Mask - Same place as Club Code (#1); simply interact with the mask the blue-haired fighter was looking at
Collectible #8-
Stairs Access - Ground floor: attempt to open the glass doors along the back wall to add this entry to your board
Collectible #9-
Exhibition: Cycle - 2nd floor: you will fight Disciples of Sean's Army (#12) in a room with coloured light bulbs. The collectible is located before this room, in a hallway similar to #2
Collectible #10-
Bodyguard - Automatically given the first time you play the level. You encounter an enemy with Juggernaut-type moves, and unlock the entry upon defeating him
Collectible #11-
Elevator - At the beginning: across the Stairs Access doors (#8), try to interact with the elevator
Collectible #12-
Sean's Army - Defeat the two Disciples in the room with light bulbs. This is after collecting #9
Collectible #13-
Museum Keycard - Automatically unlocked once you defeat the Bodyguard (#10)
Collectible #14-
Temporary Exhibition - On the fourth floor, head past the dragon shrine and collect the pamphlet on the stand
BEFORE you vault over the barrier that leads you to the Temporary Exhibition
Collectible #15-
Elevator Key - Acquired after completing the Temporary Exhibition
Collectible #16-
Exhibition: Twins - 3rd floor: collect the pamphlet from the stand (same as the two others), before reaching a room with fighters and Juggernauts
Collectible #17-
Artist Residence Door - Upon arriving at the fourth floor, turn right and head through the first set of doors. Look to your right and interact with another set of double doors. You need the Artist's Key from the Tower (Mission4, #14) to unlock this