@Samatha In my experience, collections do not factor in the search functionality in ResourceSpace. Search only “sees” individual resources not collections.
You can affect what collections a user can see, and also what resources a user can see.
You can also create “smart” collections, which are basically saved searches. And if you have the Refine search plugin installed, users can search within a search. This allows the user to drill down in a collection (or a search).
if you want to create order in ResourceSpace it is best to look to metadata on resources not segmentation in collections.
Frederick