You can follow these steps to do a selective download of your backup file:

Step 1: Click on the arrow in the Backup Module your dashboard.

Step 2: In the Backup Module of dashboard, on the right hand corner, click on Show All Backups right below Real-Time Updates section 

Step 3: Click on Files in that backup and you will be able to access all the files of that particular backup.

Step 4: Select the file or folder you want to download.