I need Changes added to the Caused by Change related list on a Parent INC to automatically show.

[Jessica49]

I need Changes added to the Caused by Change related list on a Parent INC to automatically show on the Child INC as well so we can keep better record of Incidents Caused by Changes. Is this a script within the BR? I tried through the filters and it wouldnt save. 

[Uncle Rob]

Do I understand this correctly?   A child incident should have a related list that shows Changes Caused by its Parent Incident?

That's not a solution you need script for.  You can build a custom relationship to handle that.

[Jessica49]

How do I start building that?

[Uncle Rob]

System Definition -> Relationships

Take a look at a few of them in the list to get a hang of it.

In this case...
Applies To means "where will this related list be available"
Queries from means "what kind of records will be in the related list"

Inside the function you put the query parameters. 
Current is the table you're querying from, NOT the table the related list is appearing on
Parent stores values form the record where the related list will appear.

So you'll probably build one applying to Incident Task applying to the Change Request.  And your query parameter will be something like...

current.addQuery('<whatever your caused by field is>, parent.incident());