It seems there is no duplicate option on version level.
Via the repository, it's possible to select duplicate via the context menu.
This function always duplicates the latest version.
If you select the three dots (...) in the left lower corner, and select a specific version the is no duplicate option available.
1. Make a duplicate option available on the version level.
2. If a user selects the topic on a higher level, ask the user which version to duplicate.