[SalesForce] Clone (Parent -> Child ) record with its related list using list button

You could leverage the power of External Ids to join up the objects and use the sObject Clone Method. External Ids let you dynamically match the records, without having to explicitly set the ids of the parent records being created in the clone.

Let's take the example of Account -> Opportunity -> Opportunity Product

List<Account> accts = new List<Account>{};
List<Opportunity> opptys = new List<Opportunity>{};
List<OpportunityLineItem> olis = new List<OpportunityLineItem>{};

Account acc = [Select Id, Name .... from Account];

Account accNew = acc.clone(false, true); //See sObject Clone Method
accNew.ExternalId__c = acc.Name + Datetime.now(); // set unique external Id
accts.add(accNew);

for(Opportunity opp : [Select Id, Name, ... (Select Id, ... from OpportunityLineItems) from Opportunity where AccountId = :acc.Id]){
Opportunity newOpp = opp.clone(false, true);
newOpp.ExternalId__c = opp.Name + Datetime.now(); //set unique external id

newOpp.Account = new Account(ExternalId__c = accNew.ExternalId__c); //set parent ref

opptys.add(newOpp);

for(OpportunityLineItem oli : opp.OpportunityLineItems){

OpportunityLineItem oliNew = oli.clone(false, true);
oliNew.Opportunity = new Opportunity(ExternalId__c = newOpp.ExternalId__c); //set parent

olis.add(oliNew);
}
}
}
}

insert accts;
upsert opptys; //upsert matches to accounts using external id
upsert olis; //upsert matches to opportunities using external id

You can override the clone action by creating your own interim visualforce page that utilises the standard controller of the opportunity sObject and write an apex extension controller to write your logic. Here is a really good answer that will get you going