Thank you for the clarification.
Please find attached a sample test that will open a new browser in a coded step and navigate to another page, then close it.
Please note that this approach will open the same browser as the one the test runs against. Also the rest of the actions in the second browser needs to be accomplished in code - locating the elements
and interacting with these
I hope this will be helpful to you. Please let me know in case of further questions. Thanks!