Your domain model associations are incorrect. Remove them both, and replace by drawing an association from Person to Location. That should create a 1-* association, which means that 1 location can have multiple people working there.
Now, on the Persons page, under "User details", add a reference selector widget in the lower section, and use the connector to select your association. That will let you set your Person's associated location.
On your Locations page, add a data grid inside "Location details" and select your data source over database, from the Location to your new association, to Person.
If this isn't making any sense to you, I highly recommend the Getting Started training, and the free Intro Course. If you are interested in classroom training, take a look here. The live intro course is extremely valuable in getting started with Mendix.