If you have rooted your device and removed the SD card restrictions, go to CC's "Other" settings and check the "SD Cards on Android 4.4". This option tells CC to ignore the SD card rules so you can navigate anywhere on the SD card.
Note 1: checking this option does not remove the restriction in Kitkat. If the folder(s) you choose are not actually writable, CC will fail to connect.
Note 2: this option has no effect if your device is running Android 5 (Lollipop) or later.