Query related records

Query related records

Hi:

I am trying to figure out if I can query related records on the save of a record with a look up field.

I created an app in Creator called Work Order.
Work Order has a look up to Products. In Products I have a lookup to Products for Parent Products.
When a user saves a Work Order with a Product filled out, I would like to query on all the Child product records and created Work Order Lines.

Is this possible? 

Thanks