If your Share link has previous versions, you can choose to show them when previewing it in the Web Player. You need to turn on the relevant option from the Dashboard, as seen below.

Once the option is on from the Dashboard, you see the Version History icon at the bottom right in the Web Player. Click on it to open the side panel with versions.

When viewing a previous version you can see its comments at that point in time, but cannot add new comments or reply. You can only do that in the latest version.