Database
[{"customerSchemes":[{"name":"A","startDate":new Date("2021-01-01")},{"name":"B","startDate":new Date("2021-01-05")}]},{"customerSchemes":[{"name":"A","startDate":new Date("2021-02-03")},{"name":"B","startDate":new Date("2021-02-01")}]},{"customerSchemes":[{"name":"A","startDate":new Date("2021-03-05")},{"name":"B","startDate":new Date("2021-03-01")}]}]
Query
db.collection.find({$expr:{$eq:[{$let:{vars:{a:{$first:{$filter:{input:"$customerSchemes",cond:{$eq:["$$this.name","A"]}}}},b:{$first:{$filter:{input:"$customerSchemes",cond:{$eq:["$$this.name","B"]}}}}},in:{$gt:["$$a.startDate","$$b.startDate"]}}},true]}})