The below example outlines an expression that considers all children in the dimension except one.
Sum(Except([Account].&[193].Children, [Account].&[194]))This expression consists of the following elements:
[Account].&[193].Children
This refers to all child members of the account with ID 193.
If 193 is a parent account, this retrieves all its immediate sub-accounts.
Except([Account].&[193].Children, [Account].&[194])
The Except function removes a specified member from a set. Here, it removes the account 194 from the list of children of 193.
The result includes all child accounts of 193, except 194.
Sum(...)
The Sum function calculates the total of the specified set.
It sums up all values of the accounts in [Account].&[193].Children, except [Account].&[194].