Complex relation/view Search form

Hi,

The structure

Continents -< Countries >-< Projects >-< Project_sectors

• We have a Projects content type.
• A Project can be assigned to multiple Project_sectors (Project_sectors is a taxonomy)
• A Project can be assigned to multiple Countries. (Country is a taxonomy)
• A country is assigned to a single Continent (Continent is a taxonomy).

The search engine

We need to create a search tool that would work in the following manner:
Three drop-down menus for the filtered view:

1-all continents in which there are projects in the system

• [all]
• Europe
• America
• ...

2-All countries belonging to selected continent, in which there are projects

• [all]
• Country1
• Country2
• ...

3-All Project_sectors for which there are projects, based on the selection of 1 and 2.

• [all]
• Sector1
• Sector2
• ...

[Search button]

The result

The result is a list of all project responding to the search arguments

Can anyone guide in setting this up?
I thought Views and Relation would be required... but if I could be pointed a post on this or something else. This would be so useful at this point! :)

Thanks in advance!