If you can step back from SQL and really consider what the user requires - e.g. I want to know the values of sales (which may include by Region, By Month etc).

With SSAS, you normally do not need to worry too much about the equivalent of SQL "GROUP BY". This tends to be a report requirement that is satisfied by the report designer. Remember that the report design may never be formally specified especially if end user authoring (e.g. Power View, Power BI) is being used. SSAS is really good at deally with that.

You need to make sure that the measures are available such as SUM (SalesAmount) and correctly reflect any business rules - you may have conditions etc to use from time to time as part of those rules.

Assuming that all tables in your SSAS database are correctly related to each other, most reporting requirements can be "met" with simple drag and drop. SSAS handles the navigation (equivalent of JOINs) because your SSAS database has them in it and it uses them automatically (unlike SQL relational databases with force you to repeat the JOIN logic every time.