Comparing two or more Numbers spreadsheets

I am collaborating with one other person on a macOS Numbers spreadsheet and somehow we have three copies of the spreadsheet with different changes, 1. by me, 2. by the other person, 3. by my iPhone. I would like to compare the spreadsheets to see how they differ so that we can get back to working on one spreadsheet.
Has anyone done this with KM or have any thoughts about how to approach the solution?
Thx for any insight.

I don't use Numbers, but Google Sheets allows you to track edits so maybe there's a similar feature built in to Numbers? Not really an answer to your question, but this is one of the reasons I use Sheets for collaborative things.

Be careful using Revert to previous version. I lost one of my spreadsheets doing that. I couldn't even open the version saved on Time Machine. The problem may have been sorted on the latest version of Numbers.