innobackupex --apply-log source and destination folder?

I am trying to use innobackupex --apply-log --redo-only, but every time it’s applying to the source folder, which I don’t want to write anything from the source. Any way to get around by writing to destination folder only ?

I’m not sure what exactly you mean. Let suppose you took backup on /backup/backup1/ directory and you want to prepare backup (–apply-log) on different folder by keeping backup intact before prepare on /backup/backup1/ directory.
You can make a copy of /backup/backup1/ to /backup/backup2/ directory for instance and use --apply-log on destination folder /backup/backup2/ directory.