Hide Sub-Items

Is there a way to hide selected items from the sub-list.  (I'm not sure if it's called a sub-list).

I created a 'Department' object and tagged it on the Document Metadata.  Now when I view in the M-Files desktop, I click on the arrow to the left of the document, and it expand the sub-list to department, and then would list all the files in the department.  For this screenshot, I am only showing two, but I have other departments that are showing many more.  I want to hide this 'Department' list because it expands into documents that are not directly related (other than by department creators).  How would I hide the Department object in the expanded sub-list?