we use a separate tabel caled hierachy
it has some key values like Hirachy art, customer Number, next level, Total Level
total level is a very lond C field and a program generets the Key like
123.234.345. where 234 is the next level and 123 is the to level.
the key contains al customer numbers aft the tree . There are N differt tees possible. Because the selection ot the tree is done with the art key.

The treevie is generatet from this field. Tts extremly fast if you load 20.000 customers in a tree it takes less than 60 sevonds on a local mashine.

We build a class using first microsift treeviue, but changed to DBI tree this year.
It has a selector of the tree art and then starts loding the tree.
you can select how many levels you want to load and you can got down an load dynamicly more nots.

If you are intersted in more details let me now.
dirk DS-Consulting@t-online.de