Option 1
#!/bin/sh
#
# show time machine logs
# -f = follow
PRED='subsystem == "com.apple.TimeMachine" AND processImagePath CONTAINS "backupd"'
if [ $# -gt 0 ]; then
log stream --style syslog --predicate "$PRED" --info
else
log show --style syslog --predicate "$PRED" --info | sed -e 's/ localhost / /' \
-e 's/ (TimeMachine) / /' \
-e 's/[[]com.apple.TimeMachine.TMLog/[/' \
-e 's/\.[0-9][0-9][0-9][0-9][0-9][0-9]\+[0-9][0-9][0-9][0-9] / /'
fi
Option 2
#!/bin/sh
log show --predicate 'subsystem == "com.apple.TimeMachine"' --info | grep 'upd: (' | cut -c 1-19,140-999