Selecting fields from ProductTreeLines inside a ProductTree query with Service Layer API

Hi,

I'm conscionable starting to enactment with Service Layer, and I recovered myself with a request to filter the fields returned by the Service Layer API.

In this case, we are querying the ProductTrees endpoint, which respond besides with the ProductTreeLines.

But we don't privation each the ProductTreeLines fields to beryllium responded by the server, we privation a subset only.

I cognize however to prime the fields we privation from the main entity (ProductTree) utilizing the $select query param, but I'm strugling to prime circumstantial fields from the kid entity (ProductTreeLine).

Is determination a mode to bash this?

Thanks successful advance!