View Item usage usage by user in Portal
I wonder if that's something you could do with ArcGIS Monitor? Unfortunately, the usage method is only available to AGOL, per the docs.
Here are a couple of other approaches:
Portal Logs
It's still pretty coarse, but you can go to web-adaptor-url/portal/portaladmin and pull logs from there. It won't get you what that user did, but you can at least see the frequency of their logins as opposed to "last login", to get a per-user sense of their overall use of the portal.
Groups
More relevant to your question, though, it to get item-level usage stats. The best I think you could hope for is to really strictly enforce group-based access to your content. Perhaps you already do this, but using your example above, if you were certain that only users in the "Planning" group had access to a particular planning-centric map, you could be relatively certain that the view count for that web map consists of views from that group.
Of course, that method still has a major drawback: the view count is cumulative.
Getting View Counts Over Time
Each item in the portal has a property numViews. If you're comfortable with scripting, you could easily pull the view count at regular intervals. Consider the following python code:
from arcgis import GIS
from datetime import datetime
gis = GIS('your-portal-url', 'user', 'password')
full_content_list = gis.content.search(query='', max_items=-1)
view_counts_dict = {}
for item in full_content_list:
view_counts[item.title] = [item.numViews, datetime.now()]The resulting dict object has a key for every content item in your portal (provided the user you logged in with is an admin), and for each item, the number of views and the timestamp.
That dict could easily be manipulated and exported to a running list in Excel that you summarize with a pivot table, converted to a pandas DataFrame, or even submitted as edits to a hosted table in your portal for summarizing in a Dashboard.
Again, none of the above methods is perfect, but hopefully they will help you get closer to the information you're looking for.
