It would be very useful to have the option for collections projects to automatically filter only observations from users who have joined the project, by adding a checkbox like “only from joined users”.
This would be very helpful for BioBlitz (or similair) events over large areas, as it would allow them to distinguish data from their event from that generated by the general population of iNaturalist users. While it is certainly possible for admins to filter out users by adding them individually, this can be very complicated and time consuming for large events with tens or hundreds of participants.
An example of a project where this feature would be useful is the Border BioBlitz. This event takes place over hundreds of kilometers, with teams participating in multiple locations, and hundreds of participants. Simultaneously, there are hundreds (or thousands) of iNaturalists users in the same area, uploading observations on their own. It would be great to be able to automatically use the “user” filter to be able to distinguish only the observations generated by users who have joined the Border BioBlitz project. While we can add user names one by one, but there are some important drawbacks. First, it’s very time consuming and prone to human error for a large dataset. Second, it would be nearly impossible to add all the users in real time, and for users, being able to follow the event in real time is an important outreach factor. An automatic filter would make it all quite simple.