The advanced editor option under the "allowed values" of your element, will give you access to more customizing features.

If you need to use your client/prospect selection in a calculated field and/or as the field for a conditional visibility, you will probably want to define numeric values for each of the options presented in the element. The advanced editor will allow you to type in a label (that your client/prospect will see) and a value (that the system will store) for each option.

Sometimes an element can have a large amount of options. To make it easy for your clients/prospects to view all of them, you can create groups and include your options in them. Click the "new group" button at the bottom of the advanced editor to create a new group. Grouped options will appear "indented" in dropdown elements and grouped in the same row in option elements.

In some cases, you might need to create an element with options loaded from other parts of the client/prospect profile. A great example of this is an "ownership" dropdown where the options include the client, the co-client (if any) and all family members of the household. 

To dynamically load options from other areas of the profile, use the "load items from" dropdown in the advanced editor. Each group of options may load from one group with add more button and you are able to select which element of the group should be used as the label of the options.

If you don't see any options available for the "load items from" dropdown, it is because there are no groups with add more button available in your template.