CRM 2011: working with subject tree

Hi all,

I don't know if it's the right place to ask this question.

Regarding the below subject tree sample:

item 1

item 1.1

item 1.1.1

item 1.1.2

item 1.1.3

item 1.2

item 1.2.1

item 1.2.2

item 1.3

item 1.3.1

item 1.3.2

item 1.3.3

item 1.3.4

item 1.3.5

item 2

item 3

Considering the GUID of "item 1" as input could anybody please help me with code sample to get the GUIDs of the third level items ?

Note: I know how to query the values, also I know that I need to use arrays and lists, but my problem is with using loops and nested loops to get the leafs of the tree

Thanks and best regards..