Changing the data directory path before the initial configuration of PostgreSQL 10.7.1

Hi Postgres friends,

Using Postgres 10.7.1 on Fedora core 28.  Admittedly not the latest
but am helping a colleague with a production system who needs a
PostgreSQL instance on this machine.

The default /var/lib/pgsql/data directory needs to go on another
partition with more space, let's call it /xyz, so the desired data
path during configuration is /xyz/var/lib/pgsql/data.

Is it possible to edit one of the conf files and replace
/var/lib/pgsql/data with /xyz/var/lib/pgsql/data before the
/usr/bin/postgresql-setup --initdb command is run?

Or, does /usr/bin/postgresql-setup --initdb have a command line option
to configure /xyz/var/lib/pgsql/data as the desired data directory?

Thanks.