Here is some info I found on manually configuring and mapping schemas.
Configuring LDAP Searches and Mappings
Using Directory Access, you can edit the mappings, search bases, and search scopes that specify how Mac OS X finds specific data items in an LDAP directory. You can edit these settings separately for each LDAP directory configuration listed in Directory Access. Each LDAP directory configuration specifies how Mac OS X accesses data in an LDAPv3 or LDAPv2 directory.
You can edit the mapping of each Mac OS X record type to one or more LDAP object classes.
For each record type, you can also edit the mapping of Mac OS X data types, or attributes, to LDAP attributes.
You can edit the LDAP search base and search scope that determine where Mac OS X looks for a particular Mac OS X record type in an LDAP directory.
IMPORTANT: When mapping Mac OS X user attributes to a read/write LDAP directory domain (an LDAP domain that is not read-only), the LDAP attribute mapped to RealName must not be the same as the first attribute in a list of LDAP attributes mapped to RecordName. For example, the cn attribute must not be the first attribute mapped to RecordName if cn is also mapped to RealName.
For detailed specifications of Mac OS X record types and attributes, refer to "Mac OS X Server Open Directory Administration for Version 10.4 or Later" (available at www.apple.com/server/documentation/).
In Directory Access, click Services.
If the lock icon is locked, click it and type the name and password of an administrator.
Select LDAPv3 in the list of services, then click Configure.
If the list of server configurations is hidden, click Show Options.
Select a server configuration in the list, then click Edit.
Click Search & Mappings.
Select the mappings that you want to use as a starting point, if any.
Click the "Access this LDAPv3 server using" pop-up menu and choose a mapping template to use its mappings as a starting point or choose Custom to begin with no predefined mappings.
Add record types and change their search bases as needed.
To add record types, click the Add button below the Record Types and Attributes list. In the sheet that appears, select Record Types, select one or more record types from the list, and then click OK.
To change the search base and search scope of a record type, select it in the Record Types and Attributes List. Then edit the "Search base" field. Select "all subtrees" to set the search scope to include the entire LDAP directory's hierarchy from the search base down. Select "first level only" to set the search scope to include only the search base and one level below it in the LDAP directory's hierarchy.
To remove a record type, select it in the Record Types and Attributes List and click Delete.
To add a mapping for a record type, select the record type in the Record Types and Attributes List. Then click the Add button below "Map to __ items in list" and enter the name of an object class from the LDAP directory. To add another LDAP object class, you can press Return and enter the name of the object class. Specify whether to use all or any of the listed LDAP object classes by using the pop-up menu above the list.
To change a mapping for a record type, select the record type in the Record Types and Attributes List. Then double-click the LDAP object class that you want to change in the "Map to __ items in list" and edit it. Specify whether to use all or any of the listed LDAP object classes by using the pop-up menu above the list.
To remove a mapping for a record type, select the record type in the Record Types and Attributes List. Then click the LDAP object class that you want to remove from the "Map to __ items in list" and click the Delete button below "Map to __ items in list."
Add attributes and change their mappings as needed.
To add attributes to a record type, select the record type in the Record Types and Attributes List. Then click the Add button below the Record Types and Attributes list. In the sheet that appears, select Attribute Types, select one or more attribute types, and then click OK.
To add a mapping for an attribute, select the attribute in the Record Types and Attributes List. Then click the Add button below "Map to __ items in list" and enter the name of an attribute from the LDAP directory. To add another LDAP attribute, you can press Return and enter the name of the attribute.
To change a mapping for an attribute, select the attribute in the Record Types and Attributes List. Then double-click the item that you want to change in the "Map to __ items in list" and edit the item name.
To remove a mapping for an attribute, select the attribute in the Record Types and Attributes List. Then click the item that you want to remove from the "Map to __ items in list" and click the Delete button below "Map to __ items in list."
To change the order of attributes displayed in the list on the right, drag the attributes up or down in the list.
Click Save Template if you want to save your mappings as a template.
Templates saved in the default location are listed in pop-up menus of LDAP mapping templates the next time the current user opens Directory Access. The default location for saved templates is in the current user's home folder at this path:
~/Library/Application Support/Directory Access/LDAPv3/Templates
Click Write to Server if you want to store the mappings in the LDAP directory so that it can supply them automatically to its clients.
You must enter a search base to store the mappings, a distinguished name of an administrator (for example, uid=diradmin,cn=users,dc=ods,dc=example,dc=com), and a password. If you are writing mappings to an Open Directory LDAP server, the correct search base is "cn=config, suffix" (where suffix is the server's search base suffix, such as "dc=ods,dc=example,dc=com").
The LDAP directory supplies its mappings to Mac OS X clients whose custom search policy includes a connection that's configured to get mappings from the LDAP server. The LDAP directory also supplies its mappings to all Mac OS X clients that have an automatic search policy. For instructions, see Configuring Access to an LDAP Directory and Setting Up Search Policies.
