Simple Star schema question

To al gurus:
I guess this is a simple question, but for some reason I'm having difficulty getting my arms around this.
I'll explain it in a simplified fashion keeping out most dimensions and facts:

Imagine the following one dimension table and one fact table:

Dimension Customer, showing rows below:
Customer_Key (PK), Customer_Code, Customer_Name, Master_Customer
1, SHT, Shell Technology, SHELL
2, SHM, Shell Marketing, SHELL
3, SHP, Shell Products, SHELL

My Fact Table has the following rows:
Customer_Key (FK), Revenue
1, $3M
2, $4M
3, $5M

If I want to view Total Revenue for Master Customer SHELL, will my query return the total if all these three rows (i.e. $12M)? I guess I'm struggling whether to add a Master Customer Code or not.

Simple question, but I've had a long day and my brain's fried!

Thanks for answering!

Well, when you get up in the morning, think about how the query would need to be written with or without the master customer column.