Splitting hierarchies and hierarchy levels into multiple dimensions.

I have read that Splitting hierarchies and hierarchy levels into multiple dimensions is mistake frequently made when developing the dimensional Models. Consequently i am trying not to make such mistakes. In most situations i have found the Hierachy is certainly valid to the business and will be usefull in drill down operations and serves to define the 1 many relationship within tthe dimension and limit snowflaking. I seem to however be frequently encountering the need to creat a dimension at the different hierachy levels. For example
i might start with a PRODUCT Dimension
wuth attributes alomng the lines of

Product Category
Product Brand
Product
...


But also find the business being modelled would benefit from a dimension at the Product Category level and sometimes even the Product Brand level when the granularity of the facts being modelled is changed.


Is this something that others frequently encounter.

It's always good to define the entire hierarchy in a single dimension (a kind of de-normalized structure) and let the fact be at the lowest granularity,later as the business demands we can go with the summary/aggregate tables or mat views,this gives us the full flexibility for the drill down to the lowest level when it comes to reporting