Comparing nested data in firestore

This has me stumped.

In some documents in firebase, there is a key “author” with the value being in a list of objects, one of them being firebase_uid.

In others, there is a key “author” with only one nested object, “firebase_uid: [actual uid]”.

For some reason, in the filter settings when I compare if “author” is equal to page param userId, the posts with the single object show up, but the posts which have the list of objects nested under “author”, which is the only choice it gives me in the drop down list to chose a value to compare, they do not.

How would I make sure to map the nested value in firebase, author.firebase_uid, so that it will show both? I am thinking the default author is taking in the multiple key/values and not binding if they are empty or undefined.

What do you think?