[Samba] Settings ACL question

[Sam]

Hello all,

I try to set full control permission to a "Boss" directory  for one 
group and in the same time I want to prevent this group to erase this 
top directory.

Is it possible to do that with different permission in the Boss parent 
directory?
Here is a small draw for explain :

For the moment I can't prevent a user member of Boss group to delete 
Boss directory...
Thanks for helping

Sam