Hi there, @tommydolplads… if I understand your post correctly, try these expressions and see if you get the desired results.
Also, you would need to make sure your privacy rules on the User data type allow for the searches to return the correct items, so watch our for the default privacy rule getting in the way.
By the way, you might not be trying to count items in the User data type, depending on what it means to sign up for or be on a waitlist in your app (is the waitlist the app itself or is it a data type in the app?), but the expressions should be similar regardless of what you are doing.
Hope this helps.
Best…
Mike