These fields are not configured/enabled in iRedMail-0.7.4 and earlier version by default, sorry.
You can achieve it with below settings in roundcubemail/config/main.inc.php.
NOTE: You should already have personal LDAP address book configured by default, but default one doesn't has fieldmap like below, also, you should remove '*_field' and update 'search_fields' in default setting.
$rcmail_config['address_template'] = '{street}<br/>{locality} {zipcode}';
$rcmail_config['ldap_public']["ldap_personal"] = array(
'name' => 'Personal LDAP Address Book',
'hosts' => array('127.0.0.1'),
'port' => 389,
'use_tls' => false,
'user_specific' => true,
'base_dn' => 'mail=%u@%d,ou=Users,domainName=%d,o=domains,dc=example,dc=com',
'bind_dn' => 'mail=%u@%d,ou=Users,domainName=%d,o=domains,dc=example,dc=com',
'writable' => true,
'LDAP_Object_Classes' => array('top', 'inetOrgPerson'),
'required_fields' => array('cn', 'mail'),
'LDAP_rdn' => 'cn',
'ldap_version' => '3',
'search_fields' => array('mail', 'cn', 'givenName', 'sn', 'telephoneNumber', 'homePhone', 'mobile', 'street', 'postalCode', 'l', 'c', 'o', 'description', 'departmentNumber', ),
'sort' => 'cn',
'scope' => 'list',
'filter' => '(objectClass=inetOrgPerson)',
'fieldmap' => array(
// Roundcube => LDAP
'name' => 'cn',
'surname' => 'sn',
'firstname' => 'givenName',
'email' => 'mail',
'phone:home' => 'homePhone',
'phone:work' => 'telephoneNumber',
'phone:mobile' => 'mobile',
'street' => 'street',
'zipcode' => 'postalCode',
'locality' => 'l',
'department' => 'departmentNumber',
'organization' => 'o',
),
'fuzzy_search' => true
);