After searching for a plugin to import WordPress user data into BuddyPress, I ran across this helpful but dated article on the topic: http://aendrew.com/content/importing-proprietary-user-database-buddypress-boss/
Using that as a guide I wrote 3 MySQL queries to import First Name, Last Name and Description from standard WordPress user meta data. I also added empty string checks and an if exists check to prevent duplicate data. Always make a backup first and use as needed.
/* first name import */
INSERT INTO wp_bp_xprofile_data (field_id, user_id, value, last_updated)
SELECT '2' AS field_id, wp_usermeta.user_id AS user_id, wp_usermeta.meta_value AS value, NOW() AS last_updated
FROM wp_usermeta
WHERE wp_usermeta.meta_key='first_name'
AND TRIM( wp_usermeta.meta_value ) != ''
AND NOT EXISTS (
SELECT value FROM wp_bp_xprofile_data WHERE field_id='2' AND
wp_bp_xprofile_data.user_id=wp_usermeta.user_id
);
/* last name import */
INSERT INTO wp_bp_xprofile_data (field_id, user_id, value, last_updated)
SELECT '3' AS field_id, wp_usermeta.user_id AS user_id, wp_usermeta.meta_value AS value, NOW() AS last_updated
FROM wp_usermeta
WHERE wp_usermeta.meta_key='last_name'
AND TRIM( wp_usermeta.meta_value ) != ''
AND NOT EXISTS (
SELECT value FROM wp_bp_xprofile_data WHERE field_id='3' AND
wp_bp_xprofile_data.user_id=wp_usermeta.user_id
);
/* description import */
INSERT INTO wp_bp_xprofile_data (field_id, user_id, value, last_updated)
SELECT '12' AS field_id, wp_usermeta.user_id AS user_id, wp_usermeta.meta_value AS value, NOW() AS last_updated
FROM wp_usermeta
WHERE wp_usermeta.meta_key='description'
AND TRIM( wp_usermeta.meta_value ) != ''
AND NOT EXISTS (
SELECT value FROM wp_bp_xprofile_data WHERE field_id='12' AND
wp_bp_xprofile_data.user_id=wp_usermeta.user_id
);