To find out the Parent device:

lsdev -l <device name> -F parent
Example: If we want to find out the parent device of the hard disk hdisk0, then

#lsdev -l hdisk0 -F parent

Output: fscsi0
To find out the Child device:

lsdev -p <device name>
Example: If we want to find out the child device of the fscsi0, then pls execute below

#lsdev -p fscsi0

Output: hdisk0