When your users create records in a Stacker app, you can choose whether your permission rules enforce your record filters or not.
If they are enforced, then users won't be able to create any records which do not match the filter on the permission rule which permits them to create.
If the filters are not enforced when the record is created, users will be able to create records which do not match the filter. Note that if you are only using a single permission rule this means they will be able to create records which they subsequently cannot see (due to the filter).
This setting is accessed via the "Advanced settings" option in the extra actions ("...") menu when editing the permissions for an object. It is configured separately for each permission rule you have.