Here are all the controls for Metro: Exodus on PS4.
Left Stick – Movement
L3 – Sprint
Right Stick – Look
R3 – Melee Attack
X – Jump
Circle – Crouch
Triangle – Switch Primary Weapon / Select Special Weapon (Hold)
Square – Reload / Interact
L2 – Aim Weapon
R2 – Fire Weapon
L1 – Wipe Gas Mask (Tap) / Open Equipment Menu (Hold)
1 (Hold) + Square – Open Backpack
L1 (Hold) + Triangle – Binoculars
L1 (Hold) + X – Lighter
L1 (Hold) + Circle – Night Vision
R1 – Throw Secondary / Open Weapon Menu (Hold)
R1 (Hold) – Select Secondary
R1 (Hold) + D-Pad Up – Throwing Knife
R1 (Hold) + D-Pad Down- Distraction Device
R1 (Hold) + D-Pad Left – Grenade
R1 (Hold) + D-Pad Right – Molotov
D-Pad Down – Swap Filter / Gas Mask (Hold)
D-Pad Up – Use Medkit
D-Pad Left – Flashlight / Charger (Hold)
D-Pad Right – Geiger Counter / Holdster Weapon (Hold)
Touchpad Button – Map / Journal