Hi @andyvt
According to your description, you want to get the email in the Sharepoint list according to the result of the Office Location selection in the Form.
If any misunderstanding, please kindly let me know.
I have set up a simple flow you can refer to:
This is my test list

This is my test From

Flow in details

Get the item from list which ColumnA is equal to the Office Location from From.

Get the value of ColumnB in this item

When a new response is submitted as below:

Will get the email corresponding to Location2

Hope the content above may help you.
Best Regards
If my solution helps, then please consider Accept it as the solution to help the other members find it more quickly.