In addition to Family Instances in the current (host) model, you can look for Items/ Revit Family Instances in linked models for selected Levels or Room(s) / Space(s) within the window:
"Items in room"
"Items in level/model"
"Items in level/model (space)
For example, you are currently working within a shell model that is host model for the fit-out as well as MEP models as linked models. To view / compare the Family Instances within the linked models against the planned dRofus Items:
Step 1. Open either the "Items in room" or "Items in level/model" window
Step 2: Select “Options...”
Step 3: Tick the box beside "Look for Items in linked models":
The Items in the linked model will now appear in the list over Items in Room: