I can't see a way in the embed api to implement a chart comparison between two date ranges. There doesn't seem to be anything in the options object to achieve this.
I've found two posts:
Comparing Date Ranges in Google Analytics API
Which suggests querying the first date range, then the second. I'm assuming the idea is to superimpose one ato the other, but am not sure how to achieve this.
Using Google Analytics APIs to create charts comparing data across date ranges
This one suggests OP found a solution with the same approach, but no tips on how to implement it. If anyone can point me at existing sample code, I'd be grateful.
You can do it with Embed API Third Party Visualizations:
You can recreate the demo from documentation: https://ga-dev-tools.appspot.com/embed-api/third-party-visualizations/