How to make a model to take objects within objects and duplicate the lines when this occurs?

[tarcisiomacci]

Hello! I'm new to using NodeJs and I thought your project was amazing, so I'm using it to help me.
However, I'm trying to do something that I don't understand how to execute within your project.
How can I get objects nested inside another object and the lines multiply according to the recurrence of these cases?
It's similar to a 1-to-many Inner Join.
Example:
Table A has one row with ID = X and Table B has 7 rows with ID = X and Collumn NAME = [a,b,c,d,e,f,g].
When I do the INNER JOIN the end result is a single table with 7 Rows:
ID NAME
X a
X b
X c
X d
X e
X f
X g