Hi, I've created a website with WordPress, based on a template. The website is http://www.nauta17.com. Part of the site is a portfolio page. If the page opens, all the projects in the portfolio are shown. Then you can make a selection by choosing a category, let's say A, B and C. Each project can be linked to more than one category. This works fine (it was part of the template).
What I actually would like to do is to add an extra layer to this. A, B and C are becoming subcategories of the main category 1, and I want to add a main category 2, with subcategories K and L; and main category 3, with subcategories X, Y and Z.
If, from the menu on the homepage, I click on the link to the project page, I get an overview of all projects (ALL). And I can choose between the main categories 1, 2 and 3. Suppose I click the link to category 3, I would like to get again alle projects, but now I can choose between X, Y or Z.
I hope the question is clear. Can somebody help me in the right direction with finding a solution to realise this? Thanks in advance.