bp_search_option_cpt_search( array $items_to_search )

function bp_search_option_cpt_search( $items_to_search ){
	//all the cpts registered
	$cpts = get_post_types( array( 'public'=>true, 'publicly_queryable'=>true, 'exclude_from_search'=>false ), 'objects' );

	//remove posts
	$cpts['post'] = null;
	unset( $cpts['post'] );

	//remove attachment
	$cpts['attachment'] = null;
	unset( $cpts['attachment'] );

	$cpts = apply_filters( 'bp_search_cpts_to_search', $cpts );

	if( !empty( $cpts ) ){
		foreach( $cpts as $cpt=>$cpt_obj ){
			$checked = !empty( $items_to_search ) && in_array( 'cpt-' . $cpt, $items_to_search ) ? ' checked' : '';
			echo "<label><input type='checkbox' value='cpt-{$cpt}' name='bp_search_plugin_options[items-to-search][]' {$checked}>{$cpt_obj->label}</label><br>";
			do_action( 'bp_search_settings_item_'.$cpt, $items_to_search );
		}
	}
}