For DSD files, check the DSP box in the Options popup and configure Output Format. DSD to PCM conversion first reduces the sample rate to 1/8th of the original sample rate. So, 1x goes to 352, 2x goes to 704 and 4x goes to 1405). You need to further resample those to your desired sample rate. So in the greater than 768 line, put 352. Then in 352 and 704 put in your desired final PCM sample rate. You can also set the destination folder in the Options dialog also. That should let you convert your files to the desired sample rate.
If they are ISO files, you need to extract them to DSD first.