Hi John,
I think you'll be able to create this kind of pie chart in Kibana by clicking the "Visualize" app in the side bar, and then clicking the "+" icon on the table to create a new visualization. This will enter you into the wizard. At this point, you should see a list of different types of visualizations. Click "Pie chart". Then you should be able to create a Terms aggregation over the field you want (in this case I think this is "host") and select a time range with the date picker in the top right corner. Your screen will look something like this:
Does this help?
Thanks,
CJ