Display Filtered Recordset based on Authorised users or any Conditions

Have you come across a situation where you want to show Filtered Recordset results based on some Criteria/ conditions? Please Note that I am not talking about Filtering Recordset values but Filtered Recordsets.

e.g. you have a search - Result/Detail page in which some of Filteres Recordset Results are supposed to be shown only to authorised Members.
OR
You have Search - Result pages in which you have given the Users the option of "OR" and "AND" (sorry for my terrible english, to have an idea of what i am talking about see this search page).
We will go through the two Scenarios one by one.