Why does the PID change when the find command is issued? - process

Question

I am studying and making a timeout command that exists in CentOS.
I run the sleep and find commands in the "timeout_bash.sh" file.
However, when the find command is executed, the "timeout_bash.sh" file appears to have been executed by the find command in the process list.
Can you tell me why?
Images URL : https://i.stack.imgur.com/t1U9l.jpg
#script File Name : timeout_bash.sh
#!/bin/bash
timeout_bash() {
scriptName="${0##*/}"
declare -i DEFAULT_TIMEOUT=5
declare -i DEFAULT_INTERVAL=1
declare -i DEFAULT_DELAY=1
declare -i timeout=DEFAULT_TIMEOUT
declare -i interval=DEFAULT_INTERVAL
declare -i delay=DEFAULT_DELAY
while getopts ":t:i:d:" option; do
case "$option" in
t) timeout=$OPTARG ;;
i) interval=$OPTARG ;;
d) delay=$OPTARG ;;
esac
done
shift $((OPTIND - 1))
if (($# == 0 || interval <= 0)); then
echo "Not Enter the Time. So not to execute timeout command"
exit 1
fi
# kill -0 pid Exit code indicates if a signal may be sent to $pid process.
(
((t = timeout))
while ((t > 0)); do
sleep $interval
kill -0 $$
((t -= interval))
done
# Be nice, post SIGTERM first.
# The 'exit 0' below will be executed if any preceeding command fails.
kill -s SIGTERM $$ && kill -0 $$
sleep $delay
kill -s SIGKILL $$
) 2> /dev/null &
exec "$#"
}
sleep 5
timeout_bash -t 60 find / -nouser -print 2>/dev/null >> a.txt
timeout_bash -t 60 find / -nogroup -print 2>/dev/null >> b.txt
timeout_bash -t 60 find / -xdev -perm -2 -ls | >> c.txt
timeout_bash -t 60 find / -xdev -name '.*' -print >> d.txt &