You can add a search page for custom content. Example lets talk about groups searching. We need a search page for type=groups.

This example is taken from /components/OssnGroups/ossn_com.php#L119-L133

~~~
<?php
function my_component_init(){
ossn_add_hook('search', 'type:groups', 'my_component_hook');
}
function my_component_hook($hook, $type, $return, $vars){
//$params['q'] contain query string.

$groups = new OssnGroup;
$data = $groups->searchGroups($params['q']);
$count = $groups->searchGroups($params['q'], array(
'count' => true
));

$group['groups'] = $data;
$search = ossn_plugin_view('groups/search/view', $group);
$search .= ossn_view_pagination($count);
if(empty($data)) {
return ossn_print('ossn:search:no:result');
}
return $search;
}
ossn_register_callback('ossn', 'init', 'my_component_init');
~~~

To add a menu item on search page see https://www.opensource-socialnetwork.org/documentation/view/5645/search-page-load