This function find only root categories.
App::CategorySet(NAME)->Parents(FLAG);
Flag can "short","long"
$data = App::CategorySet('blog-cat')->parents();
// Return value
/*
Array
(
[0] => Array
(
[id] => 1
[fkey] => 0
[adminref] => 1
[parentid] => 0
[image] =>
[title] => Page Manager
[description] =>
[type] => blog-cat
[generic] =>
[entrydate] => 2012-12-13 10:47:18
[lastmodified] => 2012-12-13 10:47:18
)
[1] => Array
(
[id] => 2
[fkey] => 0
[adminref] => 1
[parentid] => 0
[image] =>
[title] => Applications
[description] =>
[type] => blog-cat
[generic] => 11
[entrydate] => 2012-12-13 10:08:41
[lastmodified] => 2012-12-13 10:08:41
)
)
*/
$data = App::CategorySet('blog-cat')->parents('short');
// Return
/*Array
(
[1] => Page Manager
[2] => Applications
)*/