How to get average of items in an array of a nested field?

[learningelastic]

And a related problem...by adding properties.inventory.type: "nested" to the mapping, kibana lens can no longer access any of the inventory.* fields. I posted the problem as a separate question here:

Kibana Visualize Lens not showing nested fields

I'm not sure what I did wrong, but Kibana Lenses aren't showing me the nested field inventory.equipment. In terms of what I did, I set up an index and added a document with this script: PUT warehouse POST warehouse/_mapping { "properties": { "inventory": { "type": "nested", "properties": { "equipment": { "type": "keyword" }, "price": { "type": "float" } } }, "profile": { "properties": { "name": { …