The Kolab daemon creates a sub-process for each parent domain name space in Hosted Kolab / Kolab Now.
It does so for each domainRelatedObject, which is not necessarily also a separate database or separate root dn.
One example could be to create ou=customer.tld,dc=hosting,dc=company, with the hierarchy under ou=customer.tld,dc=hosting,dc=company containing the entries for primary domain namespace customer.tld -- all contained within the dc=hosting,dc=company database / root dn.