This dialog is viewed by selecting the 'Alternative Locations' link when backing up partitions. It is possible to select a number of destination folders or drives for backing up to. When the backup runs, each location will be tried in sequence until the first valid one is found. This will then be used to write the backup image. This is particularly useful if you plan to rotate external hard drives, each of which has been assigned its own drive letter.
There are three ways of adding folders to the list:
Type the location into the text box and click 'Add to list'.
Use the folder search icon to find the location you wish to add and then click 'Add to list'.
Directly click 'Add to list' which will open a window allowing you to select the folder / drive you wish to add.
You can prioritize the search order by clicking 'Up' and 'Down' buttons to move the position of each locations. Or 'Remove' locations that are not relevant.