adds some categories to BP Default header search (dropdown options) in order to search within this categories...

bp-search-post-cats.php

<?php
/*** based on http://buddydev.com/buddypress/making-buddypress-activity-searchable/ ***/

/* simply paste what follows in your functions.php file */

add_filter( 'bp_search_form_type_select_options', 'kendyman_seventeen_options', 10, 1);

function kendyman_seventeen_options( $options ) {
  
	$args = array(
	                'orderby'    => 'name', /* ou id ou count .. */
	                'order'      => 'ASC', /* ou DESC */
			'include' => array( 1, 5 ) /* list of category ids to include */
	              );

	$cats = get_terms( 'category', $args );
	
	foreach( $cats as $term ){
		$options['cat-'.$term->term_id] = $term->name;
	}
	
	return $options;
}

add_filter('bp_core_search_site', 'kendyman_seventeen_search_by_cat_url', 10, 2);

function kendyman_seventeen_search_by_cat_url( $url, $search_terms ){
	
	$search_which = $_POST['search-which'];
	
	if( strpos( $search_which, 'cat-' ) !== false ) {
		$search_query = str_replace('-', '=', $search_which );
		$url = site_url( '/?s='. urlencode( $search_terms ) .'&'. $search_query );
	}
	
	return $url;
}
?>

I wish display a new post type, is there a way? Thanks :*