Gorm How to new a new DB object from a DB

How to new a new db object from a db object ?

func QueryTest(db *gorm.DB) {
    var res []User
    db = db.Table("aaa").Where("aaa.id = 1")
    db.Scopes(myScope).Find(&res)
}

func myScope(db *gorm.DB) *gorm.DB {
    return db.Table("bbb").Where("bbb.id = 2")
}

In myScope, the db has a new condition where and table , but in QueryTest it has been set a table and where . What will it happen ?

In myScope I want to new a new db and doesn't inhert the pervious db where and other condition . It seems no New() function ?

func myScope(db *gorm.DB) *gorm.DB {
    return db.New().Table("bbb").Where("bbb.id = 2")
}

In some complex subqueries I need to do something like this, new a db but doesn't inherit the condition .