Find all SUID files:
find / -perm -4000 -print
Find all SGID files:
find / -perm -2000 -print

$ ls -lah test
-r-sr-xr-x  1 user  user     0B Jan 24 22:47 test
$
$
$ stat -x test | grep Mode
  Mode: (4555/-r-sr-xr-x)         Uid: ( 1000/    user)  Gid: ( 1000/    user)
$
$
$ find test -perm 4000
$ find test -perm 2000
$

find $DIRECTORY -perm /4000

find $DIRECTORY -perm /2000

find $DIRECTORY -perm /6000

find $DIRECTORY -perm /u=s,g=s

find / -perm -u=s -type f 2>/dev/null