This page should help explain some of the changes/improvements added to the software with v7 to better handle the listing fields that will contain any kind of address information.
For specifics on managing this field type go to the mapping field wiki page
By default configuration this includes the address, city and zip/postal code fields. But note the city field can be overridden by a region level if you configure it so.
For specifics on managing this field type go to the address field wiki page
By default configuration this is the state and country fields.
For specifics on managing this field type go to the region field wiki page
<tip c n>We strongly urge that you leave country as level 1 and state/province as level 2 within the GEOGRAPHIC SETUP admin tool. Even if you are only using one country and/or one state/province. These two levels are used to populate the country and state fields of the listing as well as used within the geographic navigation addon if you ever decide to use it. So if at any time you decide to use or display region data in any form, use mapping features of any kind this data or expand into other state/provinces/countries that structure is there and intact for immediate use. </tip>
<tip c n>Another important note is that if there is only one choice within a specific region (like there is only one country in use or only one state in use within a specific country or any level if you add more) that selection will be automatically assumed by the software so the client doesn't need to actually select it. If you only have the United States as a active country your clients will never need to select it as a region choice in their listing data or a select the country level region in the geographic navigation addon feature. The software will do the same for state if there is only one state. </tip>
Depending on how you have this field "used" look to the above wiki pages on how to manage it.
By default this field is a blank field where the city can be filled in by the seller/registrant. It would be managed by default within the "main settings" section of the LISTING SETUP > FIELDS TO USE admin tool. And then of course within any category specific field configurations you may have. You would set is use, requirement, editable and where it displays within "main settings" section of that page.
But you have the ability to roll the city choice into the region selection for use as a filter within the geographic navigation addon feature. We by default do not populate any 3rd level or city region level as this data can be a lot to manage. Within the United States there are MANY cities and managing the city level can be quite a management task. So we leave this level to the clients choices and needs. If you decide to manage this data for your client within the geographical region data you would set the city region level to "city" within the GEOGRAPHIC SETUP > LEVELS admin tool so that the city field is auto populated like the country and state/province data is auto filled above it.
<tip c n>If the region selection is important for the use of your site you should require selection of each level required within the LISTING SETUP > FIELDS TO USE admin tool. And note the same at the category specific field configuration level if you have category specific field configurations. </tip>