The Experience Add On allows for a new entry on the radius selector on the user interface. When a Radius First Entry has been set it will appear as the initial text in the radius drop down that the user sees on your search form. The value will be set to the default miles that you have set in Radii Options.
You must have the Experience Add-on to change the Search Layout appearance, and along with other add-ons, also allow you to to use the shortcode on SLP WP page.
These shortcodes only apply to the Search Layout admin setting when you have the appropriate Add-on installed and activated.
This shortcode provides a simple mechanism to place standard search form elements on a custom search form layout, including the wrapping divs and classes around labels and input fields.
Places a search form button on the search form.