Lookup fields are a concept in BillingPlatform that allow you quickly loop up pertinent information on the fly while inputting new records. This feature can drastically reduce time switching between tabs to find customers information that may lie elsewhere in the application.
Aside from being able to reference other system or custom entities, a lookup can allow reference to an entity itself and allow the concept of nested records (e.g. similar to nested accounts, packages, and products).
In order to create a new lookup field, follow the instructions in the entity field creation and choose the field type of lookup. While the details reside in the tutorial, the differentiator for lookups is the lookup field entity. The lookup entity is the entity you will access for information.
Lookups in Use
Lookup fields in use will have the lookup icon placed to the right of the field, resulting in a field that looks similar to below.
Select the icon to open the lookup window. The overall appearance of the window will be the same across use, what will change is the results, which is dependent upon the setup, when you select the lookup field entity. The window will look similar to below.
The new window will allow you to search for records within the defined entity. Selecting a record will attach the record to the origination field.
Object reference can be done for entities with lookup fields by navigating through the <fieldname>Obj notion on when using the object reference UI. Examples of such situations can be when creating reports, dealing with workflows, and referencing inter-connected objects in templates (e.g. invoice templates, email templates, etc.). Clicking on these fields will allow you to drill down to the fields in that object. If there are lookups in the target object, clicking on them will allow you to drill into them even further, allowing you to work your way into multiple objects as long as there are links (e.g. lookup fields) to them.
Furthermore, if the entity has a lookup to itself, the Parent<Entity Name>Obj field will be available for selection. This is particularly useful if you need to reference parent fields for nested entity records. In the screenshot below, the parent of the account record that is directly linked to the activity record is accessed: