If you want to be able to copy segments that you already have, with the same tags, same rules, you can do it like this:

When you are on the segment you want to copy

1. Click on 'Options'
2. Then on 'Create copy'

When the segment is copied and ready, you will find the copied segment under your segments, with the same name as the segment you copied from with a "copy" at the end as you can see in the image below. You can change the name of the segment by going in and clicking on the name and then clicking on the checkmark to save the new name of the segment.