The RHEL 7 / CentOS 7 comes with systemd (System Management Daemon) which is a init system uses target instead of Runlevel Numbers but the concept is the same.
To List, all active units/services just run the below command.
[root@oracledb ~]# systemctl list-units ---> To list all Units/Services
Or you can filter the unit list to find targets by using the below command.
Read More - https://www.itsmarttricks.com/change-runlevel-in-rhel-7-centos-7-with-systemd-using-systemctl/