If you have taken a backup of your database using the "Backup" button in Geneious, and chosen to "Archive all data and settings" then the backup.zip file that is produced will be an entire database copy. When this is restored using the "Restore backup" function, the backup is extracted into a new database. When "Load Restored Data" is clicked at the end of the restore process, this replaces the existing database in the Sources panel in Geneious.
You can switch back to the original database by going to Tools -> Preferences and changing the data storage location back to the original data folder. If you are not sure where this is, it will most likely be a folder called "Geneious X. Y Data" (where X and Y are version numbers for Geneious), which is located in your User folder.
If you want to have both the restored backup data and the original data in a single database folder, then you will have to export the files from one database and import them into the other.
You can do this as follows:
1. Restore your backup by going to File -> Restore Backup, and click "Load Restored Data" at the prompt.
2. In the Sources panel, select the "Local" folder so that all subfolders in the database are selected. Alternatively, if you only want to keep a few folders from the backed up database, just select those folders.
3. Export the folders you have selected by going to File -> Export -> Export Folder. This will export the folders as a *.geneious file. Make sure to note where you save this file.
4. In Geneious, go to Tools -> Preferences and, in the "General" tab switch the "Data Storage Location" back to your original database. The data from your original database should now load.
5. Import the folders from step 3 by dragging the *.geneious file you exported from the restored backup into Geneious.