The Firebase Android SDK for analytics provides a method named setUserId(String id), now i enabled firebase logging and every time i called the method setUserId(1234) i see this in the logs Setting user property (FE): _id, 1234.
My question is how come the Firebase dashboard does not let us filter by this property, there is no property not for userId and not _id, i even tried to add _id as a property in the dashboard but Firebase does not allow property names to start with an underscore.
Do i really have to stop calling that method and just do setUserProperty("userId", 1234) or am i missing something...
I have spent a few hours on this and found the answer i was looking for more or less, hopefully this might save someone else some time.
The only way to filter by Firebase's User Id property is by creating an audience, there you will be able to pick the user id property that is supplied from the setUserId(String id) method.
It is a downer though because you won't see any events for the user/user's you want from before the audience was created.
In audience you have to select contains, exactly match or regular expression for a field.
So to filter for a user you have to add all your users to the audience, which looks cumbersome.
Isn't using setUserProperty is better? Have you faced any problems with using it ?
