Hello.
If you are using the Booking Calendar Free version, then you can redefine one of exist fields from the Booking > Settings > Fields page to enter or select some specific location.
In the paid versions of Booking Calendar possible to have more advanced any number of fields, including entering city, zip code, and address fields. Please use shortcode generator at the right side of the Booking > Settings > Fields page for the fast and correct creation of booking form fields in the paid versions of Booking Calendar. You can test Booking Calendar live demos at this page https://wpbookingcalendar.com/demo/ to be sure in functionality and do not have misunderstanding.
P.S. Please note, the selections of the country from the predefined country list exist in the Booking Calendar Business Small and higher versions. In the Booking Calendar Personal version you need to define all countries in selectbox manually.
Kind Regards.
