I have a lookup field on Account to a custom object. The lookup dialogue, allows me to search on the record's Name. However, I want to search on one more field. Is there a way to search from a lookup dialogue to more fields?
To get autocomplete results in lookup field, you can only perform search on first two fields mentioned in Search Layout of the lookup object (parent) and this can only be done for some specific field types mentioned below for custom objects.
To get results on lookup dialog box (by clicking on enter), then you can perform search in all the following types of fields for Custom Objects.
All custom auto-number fields and custom fields that are set as an external ID (no need to enter leading zeros)
All custom fields of type email and phone
All custom fields of type text, text area, long text area, and rich text area
For all other objects, you can refer this link
If we add formula fields to perform search on unsupported types, it works on recently opened records in autocomplete but not full search.