Here is a view of that side panel from a recent search. Notice it has been renamed to aggregations in the current UI. Below are the fields metadata.product_name and metadata.event_type. In our result set, we have 143 events and each of these fields has a value in every event, so the value on the far right is 143. Within the parenthesis, we can see that there are 5 distinct values for product name and 4 for event_type.
When I expand the field, I see the 5 values for metadata.product_name and the 4 details for metadata.event_type within. In this case Office 365 is one of those 5 distinct values and 11 events are of that product_name and 19 of the 143 event_types is USER_LOGIN.

As I mentioned eariler, not all events will have a field populated. Here we have the target.application field which is only populated in 24 of the 143 events in our search. Of those 24 events, there are 7 distinct applications and the AzureActiveDirectory value is seen 10 times of the 24 times that field is populated.

Hope that helps!
Here is a view of that side panel from a recent search. Notice it has been renamed to aggregations in the current UI. Below are the fields metadata.product_name and metadata.event_type. In our result set, we have 143 events and each of these fields has a value in every event, so the value on the far right is 143. Within the parenthesis, we can see that there are 5 distinct values for product name and 4 for event_type.
When I expand the field, I see the 5 values for metadata.product_name and the 4 details for metadata.event_type within. In this case Office 365 is one of those 5 distinct values and 11 events are of that product_name and 19 of the 143 event_types is USER_LOGIN.

As I mentioned eariler, not all events will have a field populated. Here we have the target.application field which is only populated in 24 of the 143 events in our search. Of those 24 events, there are 7 distinct applications and the AzureActiveDirectory value is seen 10 times of the 24 times that field is populated.

Hope that helps!
Thank you very for this explanation. It is very helpful.