Dimension Groups / Hierarchies for Strings. Like Product Hierarchy, Or Region Hierarchy

[Dovile]

How can one implement below in looker?

Let's say we have a sales report, and content is sliced and diced via common  dimension groups:

• Product Hierarchy: Group, Category, Type, Product
• Geo: Area,  Continent, Country, Region, City

Questions:

1. How to make these dimension appear together in the explore?
2. Any ways to re-use it across the explores? No matter if we calculate, revenues, costs or some other metrics - these hierarchies are the same. How not to have it to retype it. 
3. How have multi-drill sets? Maybe one user wants to drill to the measure by Product Hierarchy, And another - by Geo. 

Basically  how to have similar funtionality with sting