You can see a list of all the MultiMaps in your cluster by clicking on the MultiMaps menu item on the left panel. A new page is opened on the right, as shown below.
You can filter the MultiMaps shown and you can also sort the table by clicking on the column headers. Clicking on a MultiMap name opens a new page for monitoring that MultiMap instance on the right.
MultiMap is a specialized map where you can associate a key with multiple values. This monitoring option is similar to the Maps option: the same monitoring charts and data tables monitor MultiMaps. The differences are that you cannot browse the MultiMaps and re-configure it. Please see the Managing Maps.