One option would be to store the actualy backups localy on the DC or on a Cifs share at the location where the DC resides. If you right click one of your collection folders and then select properties you will see that you have a Tab called "DC Storage".
This tab includes the following elements:
Save Backups on the DC Being Backed Up or a UNC Share. Select this check box to save backup files either on the domain controller being backed up or on the Universal Naming Convention (UNC) share you specify.
Enter the location for backup files in the Backup file name format box. If you specify a UNC share, backup files will be directly streamed to that share from Backup Agent installed on the DC being backed up. Backup Agent accesses the DC being backed up and/or the specified UNC share under the account specified on the Agent Settings tab.
Backup file name format. Use the provided space to specify format for paths and names of .bkf files where to store backups.
If you want to store backups on remote computers, the path must include UNC names.
The path format may include optional expressions that enable the automatic creation of subfolders.
The file name format may also include expressions. For example, you might specify
As a result, backups for different computers will be saved in separate subfolders.
In addition, the file name of each backup will be composed of the date and time of the backup creation.
Expression. Click this button to specify optional path and file name notations in Backup file name format. You can choose the following expressions:
Domain (%DOMAIN%). Name of the home domain of the computer being backed up.
Computer name (%COMPUTERNAME%). Name of the computer being backed up.
Date and Time (%DATETIME%). Date and time of the backup creation.
Sample path and file name matching the specified format.
View an example of the path and file name that matches the format string supplied in Specify format for backup file name.
For each computer, delete all backups except the last <Number>. Select this check box to retain only a limited number of backups for each computer, and then specify the number in question.
This check box can be selected only when Recovery Manager for Active Directory stores backups separately.
To ensure that Recovery Manager for Active Directory does so, add the %DATETIME% expression to the path or file name in the Backup file name format box.