Here's how I dump .xci partitions:
1) Place a populated prod.keys file in .switch\ (You can get this file with kezplez-nx)
2) Grab hactool and extract it to a folder
2) Place your .xci in the same folder as hactool.exe
3) Open a terminal window/command prompt in that folder
4) Enter "hactool.exe -x -txci YOUR_XCI.xci --outdir=Extracted_XCI" (With "YOUR_XCI" being replaced with the .xci name)
5) The extracted partitions are in Extracted_XCI\
If you're looking for ease of use, here's a small batch I wrote a while back.
Just place it into your hactool folder and drag your .xci onto it (the .xci doesn't need to be in the hactool folder)
and it will extract the partitions into Extracted_XCI\.
(Bear in mind you must still have a populated prod.keys at .switch\)
Thanks