I believe it is outside from the main DIT because the differents suffix. and i saw this documentation:
https://wiki.zimbra.com/wiki/Zimbra_Directory_Service_(LDAP)at the second Picture there are two DIT.
I solved my problem by building a second Database with the wanted Suffix by adding this ldif:
dn: olcDatabase={2}hdb,cn=config
objectClass: olcDatabaseConfig
objectClass: olcHdbConfig
olcDatabase: {2}hdb
olcDbDirectory: /var/lib/ldap/<NEWDIR>
olcSuffix: <new root DN>
olcAccess: {0}to attrs=userPassword,shadowLastChange by self write by anonymous auth by dn="cn=Manager,<new root DN>" write by * none
olcAccess: {1}to dn.base="" by * read
olcAccess: {2}to * by dn="cn=Manager,dc=<new root DN>" write by * read
olcLastMod: TRUE
olcRootDN: cn=Manager,<new root DN>
olcRootPW: <manager password>