Yes, it's generally quite straight forward. However, remember that security in MSAS is based either on the dimensional characteritcs or on item data. (As opposed to a hieararchy definition).
You'll first need to layout your business rules arround the security model (i.e. in most security models, you can get access at multiple levels and multiple types). However, I will suggest the following:
- At it simplest, you can grant access (via roles) to specific nodes.
- For a simpler model, you should be able to use the user function at the data points to turn access on / off dynamically.
- You'll probably need to implement a many to many dimension.
- Take a look at the parent-child dimension. But remember, it's a one to many relationship (i.e. can a user id exist in more than one location?)
Some of this may depend on how many data rows you're planning and the type of hardware you'll run on.