I have the following Category structure setup:
-- Page---- Sub Category------ Item------ Item 2---- Sub Category 2------ Item 3
I have also defined each Sub Category in the Categories list.
Each item has a property "Secondary Categories" which is of type CategoryProperty. Essentially what I'm trying to do, is return a list of Items relevant to the sub category, and secondary categories. For example, if Item 3 has a secondary category "Sub Category", then if I am viewing Sub Category page, I should be see a list of all Items under Sub Category, and Item 3.
At the moment, I can only think of performing two separate searches, one which will return the children of the SubCategory, and another which will perform a FindPagesWithCriteria that will add a CriteriaProperty based on the Category (being Sub Category), which this search starting at the "Page" reference id. I would then join both lists together for the final list.
From what I understand, you cannot perform an AND/OR for a Criteria search, i.e. if I had another property on the Item pagetype called "MainCategory", instead of performing two searches, add the Criteria for "Main Category" dependant on the page I am currently viewing.
Hope this makes sense.