app/views/images/edit_fields/_location.html.erb
<%=
f.input :location,
as: :multi_authority_controlled_vocabulary,
placeholder: 'Search for a location',
authorities: [:geonames, :tgn],
### Required for the ControlledVocabulary javascript:
wrapper_html: {
data: { 'field-name' => 'location' }
},
required: f.object.required?(:location)
%>