How can I create a custom navigation tree with Twonky 4.4.6

[orinoko]

Hi together,
I want to create the following tree for MUSIC:

Titles
....|-- ABCDE
............|---A
............|....|--- All titles with A
............|---B
.................|--- All titles with B

..... and so on....

How can I configure this with Twonky 4.4.6 ?

ThanXX,
Orinoko