1. make the file available for everyone to access
2. limit access to the file to specific members of the network
3. keep it only for yourself
If you limit access to a file to only specific network members, only the members you shared it with will see it displayed in the files tab. The file will also show with an orange padlock alerting the network member that a limited group has access to the file. If you click in to the details view for the file, you will see exactly who the file was shared with.
If a file is not shared with a network member, it does not appear in their files tab at all.