How to set the "Fields" which only contain the matched?

Elastic Stack Elasticsearch
1

{
name:"bach",
introduction:"bwv1004"
works:[
{work_name:"bach bwv1004"},
{work_name:"bach violin concerto"}
]
}

I expect to get following answer when searching "bwv"
{
introduction:"bwv1004",
works:[
{work_name:"bach bwv1004"}
]
}

2

It looks like works is an array, I'm not sure you can just return part of that in a query though.