For example, from the path C:\Dropboxes\DeviceType\LogFiles\DeviceName\Tuesday\ the report should just show "Tuesday".
Split function is the first thing that comes to mind and that's what I saw in SSRS list of expression methods and used.
=Split(Fields!FolderPath.Value.ToString(),"\",-1)(Split(Fields!FolderPath.Value.ToString(),"\",-1).GetUpperBound(0)-1)
The second split is to get the count of total elements as I need to find the last element of the split array, and the folder path depth is not static.