The backup file server stores backups from all the NSX Manager nodes. To get the list of backups so that you can find the one you want to restore, you must run the get_backup_timestamps.sh script.

The script can be found on each NSX Manager appliance at /var/vmware/nsx/file-store/get_backup_timestamps.sh. You can run this script on any Linux machine or NSX-T Data Center appliance. As a best practice, copy this script after installing NSX-T Data Center to a machine that is not an NSX Manager so that you can run this script even if all the NSX Manager nodes become inaccessible. If you need to restore a backup but have no access to this script, you can install a new NSX Manager node and run the script there.

You can copy the script to another machine or to the backup file server by logging in to the NSX Manager as admin and running a CLI command. For example:
nsxmgr-1> copy file get_backup_timestamps.sh url scp://admin@server1/tmp/
admin@server's password:
nsxmgr-1>
The script is interactive and prompts you for the information that you specified when you configured the backup file server. You can specify the number of backups to display. Each backup is listed with a timestamp, the NSX Manager node's IP address or FQDN if the NSX Manager node is set up to publish its FQDN, and the node ID. For example,
admin@host1:/home/admin# ./get_backup_timestamps.sh 
Enter file server ip:
10.10.10.20
Enter port:
22
Enter directory path:
/home/nsx/backups
Enter number of latest backup or press Enter to list all backups:

root@10.10.10.20's password: 
Latest backups:
[Backup timestamp; IP address/FQDN; Node id]
2019-01-22;09:16:43 nsxmgr.example.com 41893642-597b-915f-5117-7da576df4ff2
2019-01-22;09:14:42 nsxmgr.example.com 41893642-597b-915f-5117-7da576df4ff2
2019-01-22;09:13:30 nsxmgr.example.com 41893642-597b-915f-5117-7da576df4ff2
2019-01-22;09:01:52 10.10.10.77 35163642-6623-8f6d-7af0-52e03f16faed
2019-01-22;09:00:33 10.10.10.77 35163642-6623-8f6d-7af0-52e03f16faed