You "probably" could run two instance of MySQL.
First - they would have to run on separate ports.
Two - their service instances would have to have different names.
You "might not" be able to use them concurrently. I can think of a bunch of reasons for that.
I also have no real idea why you would want to do that. All the actual database instances are held separately and can be walled off with a good configuration scheme.
This is 'out-of-scope' for XAMMP, so you are on your own as to if it will work, and how.
MySQL is governed by several things, primarily by the my.ini (in XAMPP) or the my.cnf (standalone) configuration files. You should peer into them for wisdom.
Last 'I will point out part' - you completely failed to mention one important thing! - the VERSIONS of everything involved - Windows, XAMPP and MySQL.
These are all just 'my opinions'