Xcode Snippets are snippets that can help you in your programming routine. Sometimes, after Reinstalling Xcode or Updating OS you can need to transfer your snippets to move them to the new version of Xcode.
If you want to know, where is the folder with Xcode Snippets on your Mac, here is the answer:
Open Finder on Mac
Press Go > Go to folder
After that copy files from this folder to a safe place. Later when you will install the new version of Xcode, again go to ~/Library/Developer/Xcode/UserData/CodeSnippets and paste them there.