As I understand you use Replace Dn suffix option. This option enables replacing suffixes, for example:
Pattern - dc=test,dc=com
Replace - o=example
Your exported data:
- cn=a,dc=test,dc=com
cn=b,dc=test,dc=com
cn=c,dc=test,dc=com
The result wil be:
- cn=a,o=example
cn=b,o=example
cn=c,o=example
