BBpress search function to ONLY show the title of the topic on wordpress

/**
* Include bbPress 'topic' custom post type in WordPress' search results */

function ntwb_bbp_topic_cpt_search( $topic_search ) {
    $topic_search['exclude_from_search'] = false;
    return $topic_search;
}
add_filter( 'bbp_register_topic_post_type', 'ntwb_bbp_topic_cpt_search' );

Hi, I just added the bbpress search code as above to my wordpress website, and it works too fine. However, some private topics are also show up. How could I use this search function on my main wp search function( at here which I use 3Cliks theme: ) but not in built-in bbpress search funtion and not include the private topic. Or maybe it could ONLY shows/index the topic title in search result pages but NOT content(excerpt, description, content).

This is my question and problem regarding bbpress search engine. Hopefully someone can enlighten me.

I also posted on here but still couldn’t find the answer yet:

Thanks in advance.

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