filter vocabulary from vocabulary I have several vocabularies; let's assume they are the following ones:


v1, with terms v11,v12,v13
v2, with terms v21,v22,v23
v3, with terms v31,v32,v33


I have a product category. When you hit the product category, I want that a page appears showing drop down menus of the above vocabularies, and the drop down containing their terms. 


How can this page be called from the click on the product category?
Now the main problem I want to solve is when the page containing the drop down menu appears, and the user clicks on a particular term of a vocabulary, that action filters some terms in the other drop down menu. For example, if v11 is selected in vocabulary v1, then with v2 only terms v22 and v23 are allowed, and in v3 only v31 is allowed so when you select term v11 the other menus should only show the allowed term. Also when a term is selected, the below section of the page should show only those products (teaser or table) satisfying the attributes as selected in the terms. And we have two choices in vocabulary v2 we can select either v22 or v33 which will further filter the search criteria of products in that category.


An example can be seen on this site.

In the left side menu, go to detection and ranging, and hit on laser measurement technology. The page which appears has several drop down menus; I want to acheive the same functionality.
Essentially, you want a hierarchical 'drill down' through taxonomy to narrow a search? If I'm interpreting this correctly, you're looking for something like Hierarchical Select, a module that does just that in the form of an input widget. I don't have personal experience with the exposed filter implementation, but it sounds like it exists.

http://drupal.org/project/hierarchical_select

http://drupal.org/node/720268