Você pode usar mod_authn_alias para criar aliases para seus provedores. Houve um exemplo em esta questão para praticamente o mesmo caso de uso:
<AuthnProviderAlias ldap alpha>
AuthLDAPBindDN "CN=Subversion,OU=Service Accounts,O=Alpha"
AuthLDAPBindPassword [[REDACTED]]
AuthLDAPURL ldap://dc01.alpha:3268/?sAMAccountName?sub?
</AuthnProviderAlias>
<AuthnProviderAlias ldap beta>
AuthLDAPBindDN "CN=LDAPAuth,OU=Service Accounts,O=Beta"
AuthLDAPBindPassword [[REDACTED]]
AuthLDAPURL ldap://ldap.beta:3268/?sAMAccountName?sub?
</AuthnProviderAlias>
# Subversion Repository
<Location /svn>
DAV svn
SVNPath /opt/svn/repo
AuthName "Subversion"
AuthType Basic
AuthBasicProvider alpha beta
AuthzLDAPAuthoritative off
AuthzSVNAccessFile /opt/svn/authz
require valid-user
</Location>