Context: We have implemented RUM via APM and want to get an aggregated count of visits by url from that data.
If you look at this screenshot of a search (done via discover) you will see that
transaction.page.url is showing up in the column:
transaction.page.url is not part of any mapping property in my apm-* index and it also doesn't show up when I try to query by that property.
So where is it coming from? And how do I index unique page visits using it?