$ cd /sys/class/backlight/intel_backlight
$ $ ls -l
total 0
-r--r--r--. 1 root root 4096 May 27 22:09 actual_brightness
-rw-r--r--. 1 root root 4096 May 27 22:17 bl_power
-rw-r--r--. 1 root root 4096 May 27 22:17 brightness
lrwxrwxrwx. 1 root root    0 May 27 22:09 device -> ../../card0-eDP-1
-r--r--r--. 1 root root 4096 May 27 22:17 max_brightness
drwxr-xr-x. 2 root root    0 May 27 22:09 power
lrwxrwxrwx. 1 root root    0 May 24 17:12 subsystem -> ../../../../../../../class/backlight
-r--r--r--. 1 root root 4096 May 27 22:17 type
-rw-r--r--. 1 root root 4096 May 27 22:17 uevent
$ getfacl bl_power brightness
# file: bl_power
# owner: root
# group: root
user::rw-
group::r--
other::r--

# file: brightness
# owner: root
# group: root
user::rw-
group::r--
other::r--