MongoDB Query Optimization using Multiple $lookup's and $group - mongodb

Question

This is a simplified schema of the database I am working with:
Collection: documents
{
"_Id": "1",
"business": "e.g food",
"relationships": "192",
"components": "ObjectId(34927493..)",
"_Score": "10",
...
}
Collection: components
{
"_Id": "280948304320",
"assessments": "8394",
"relationships": "192",
"results":"ObjectId("82394792343")...."// can be many results
}
Collection: results
{
"_Id": "7978394243",
"state": "severe",
"parentComponent": "ObjectId("28907403")"
"confidence":"0.5"
"category":"Inspection"
}
I have a mongoDB query which is taking 200+ seconds to execute. Here it is below:
db.documents.aggregate([
{$match:
{ "business" : "food"}
},
{
$unwind: "$components"
},
{
$lookup:
{
from: "components",
localField: "components",
foreignField: "_id",
as: "matching_components"
}
},
{
$unwind: "$matching_components"
},
{
$lookup:
{
from: "results",
localField: "components",
foreignField: "parentComponent",
as: "list_results"
}
},
{
$unwind: "$list_results"
},
{$group :
{ _id : '$list_results.state', count : {$sum : 1}}
}
])
I am wondering if there is any way for me to improve the performance of this query. I tried using a group statement in the beginning of the query that groups the documents into their business category, but that did not work as I realized it removes the fields needed for the rest of the query. I indexed for all the fields that I am looking across.
Just to be clear I want to group the documents by their business field. Then I want to map to another collection called components that contains results. After I use another lookup to finally map to the results collection, I want to ultimately count the frequency of each state by business. Currently as you can see, I am using a match in the beginning instead just to see if the query works for one business type. Though the query works, it is taking around 140 seconds.
EDIT: Example Result from this Aggregation:
{
"_id" : State1",
"count" : 90699.0
}
{
"_id" : "State2",
"count" : 448869.0
}
{
"_id" : "State3",
"count" : 71399.0
}
{
"_id" : "State4",
"count" : 513928.0
}
{
"_id" : "State5",
"count" : 765509.0
}