Mapsly allows an object to be positioned on the map based on the location of a related object referenced by a look-up field. For example, a Deal in Zoho CRM or Opportunity in Salesforce doesn't have their own address fields but reference an Account object, so the Account's location can be used to plot Deals and Opportunities on the map without the need to create additional custom fields.
To indicate that that an object must use the location from a related object, simply select the look-up that reference this related object in the address selector:
IMPORTANT! Please make sure the look-up you'd like to select is checked in the list of fields in this object (otherwise it would not appear in the field selector).