db={"company":[{_id:ObjectId("5a934e000102030405000000"),companyName:"Meta",address:"123 Facebook Lane",status:"Client"}],Projects:[{_id:ObjectId("5a934e000102030405000002"),companyId:"5a934e000102030405000000",name:"Test Project",price:97450,},{_id:ObjectId("5a934e000102030405000003"),companyId:"5a934e000102030405000000",name:"Test Project 2",price:100000,}]}

db.company.aggregate([{$match:{_id:{$in:[ObjectId("5a934e000102030405000000")],},status:{$in:["Client"]},},},{$lookup:{from:"Projects",let:{companyId:{$toString:"$_id"}},pipeline:[{$match:{$expr:{$eq:["$companyId","$$companyId"]}}}],as:"projects"}}])