A great option could be to have an option to unfold the group facet "ITEMTYPECAT". If I use the example given in the manual : it's great to filter on "Movies" items, but I don't have a Blu-ray player, I would be happy to unfold the "Movies" category to only select the "DVD" item type !
Yes! You can do a search and then (I believe) use the faces to further narrow the search, but it would be nice if it was an option in the advance search.
There has been some discussion about the display in staff interface/OPAC on bug 32258. This here was meant to allow OPAC users to see the grouped item types and select one ore more, right? Would this need to be optional?