Thanks, mercime, but the link is not even close to what we are discussing (what I am discussing, anyway).
What I’m after is a search page (not search results page) that allows selecting certain values for certain fields and search on the basis of that.
e.g. I may have 3 custom fields
Marital status: Single, Divorced, Separated, Widow/Widower, Married (dropdown)
Country: (freeform or dropdown)
Favorite ice-cream flavor: (freeform)
Then I want a search page where a visitor can see all fields, including custom fields
Marital status (checkboxes)
Country (checkboxes or freeform)
favorite ice cream flavor (freeform)
and can search for users who
are (single) OR (widower)
AND
are in (germany) OR (austria)
AND
like (rocky road)
flavor ice cream