“personal_options_update” action hook is use to a save the extra profile fields section data. This is used with “show_user_profile” action hook.

Copy and paste this sample code in the theme functions.php file

function save_user_profile_extra_fields_callback( $user_id ){

    if ( !current_user_can( 'edit_user', $user_id ) ){
        return false;
    }
    if( isset( $_POST['comp_address'] ) ){
        update_user_meta( $user_id, 'comp_address', sanitize_text_field( $_POST['comp_address'] ) );
    }
}

add_action('personal_options_update', 'save_user_profile_extra_fields_callback', 20, 1);

To check on how to add extra profile fields please see HERE