Insight read only field that can pull an attribute of an attribute?

[Steve Letch]

Scenario:

We have a read only field that pulls an object type based on the $reporter that raised the Jira ticket . The object type is called AD Users.

An attribute of this objecttype is another object type called Department.

An attribute of the Department object type is 'Sub Team Responsible' which links to the object type 'Sub Team'

I want my read only field to essentially look inside my read only field, see the Department attribute, find the sub team attribute and put it into my read only field. I've been looking at this for a few weeks and haven't been able to get it exactly how I want.