Multiple Custom Categories in A Page Template

I’d like to create a page that pulls specific categories into it like the page as illustrated here:

http://codex.wordpress.org/Pages#Creating_Your_Own_Page_Templates

I looked at the above page for a sample template for multiple custom categories. I’m wondering if there is a specific loop I should use to pull the results of a specific ‘category’ that is listed in another category? For example, I have three main categories on my website that I’d like to be used to pull information for users.

Services (Parent of: Hairdresser, Beautician etc)

Location (Parent of: Australia, New Zealand etc – several Countries)

Region (Parent of: Victoria, ACT etc – All Regions)

What I want the script to do:

I want a page to display ALL ‘Hairdresser’s in ‘Victoria’ ‘Australia’ is there a specific loop I use to only pull ‘Hairdressers’ from those categories? If someone could post me a sample template I’d be grateful.

I’d like to make a generic page template with code that I can just adjust the categories in to suit my needs of any THREE categories of my choosing when I wish to make certain pages.

Many thanks for help in advance.