Return all levels below a specific member - sql-server-2012

Question

In the following I was hoping to return all of the tree below the member Engineering.
I'm guessing I'm misusing IS?
Should I be using membervalue?
I thought using the specific member would be more efficient?
WITH
MEMBER [Measures].[LevelName] AS
[Employee].[Employee Department].Level.Name
MEMBER [Measures].[LevelNumber] AS
[Employee].[Employee Department].Level.Ordinal
SELECT
{
FILTER(
[Employee].[Employee Department].AllMembers,
[Employee].[Employee Department].[Department] IS
[Employee].[Employee Department].[Department].&[Engineering]
)
} ON 1,
{
[Measures].[LevelName],
[Measures].[LevelNumber]
} ON 0
FROM [Adventure Works]
Here is the error message:
Executing the query ... Query (10, 3) The Is function expects a level
expression for the 2 argument. A member expression was used. Execution
complete

Answer 1

You don't need to use the FILTER function to obtain all child members belonging to a specific member. Just do something like this instead:
SELECT
{
[Employee].[Employee Department].[Department].&[Engineering].CHILDREN
} ON 1,
...
If you want the entire tree below a specific member, use the DESCENDANTS function:
SELECT
{
DESCENDANTS([Employee].[Employee Department].[Department].&[Engineering],
[Employee].[Employee Department].[Department], AFTER)
} ON 1,
...