誰を訪ねて来ましたか？って英語でなんて言うの？

1)誰に会うために来て頂いたのでしょうか？

2)誰かと会うご予定がございましたか？

参考になれば幸いです。

このシチュエーションでよくいう言い方は
1) Do you have an appointment?
「ご予約がありますか？」
ではないでしょうか。

もし「誰を訪ねてきましたか？」と言うなら
2) Who would you like to speak with today?
とも言えると思います。

相手の会社を聞く場合は、
Could I ask which company you are with?
と言えます。

ご参考になれば幸いです！

All of these questions are polite but if you want to be extra polite you can add ‘May I ask...’ before the question. This way you are asking for permission to receive the information as well as asking for the information itself.

Begin your request with the word 'please' always. This will ensure that your question is polite.
The final sentence is more formal. You can use 'please can you tell me', or 'please let me know'.
Once they have answered, follow up with 'Thank you.'

If someone has come to visit your company, and you want to ask them who they are here to see and which company they are from, politely, you could say either of the following: "Who are you here to see? Which company are you with?" or "Are you here to visit a particular person? What company do you belong too?".

If you are going to ask the visitor to your company who he/she is there to see and also from which company he/she comes, it would be ideal to use a compound sentence instead of two simple sentences. A compound sentence is one that uses two independent clauses joined by a conjunction such as 'but' or 'and'. If you decide to use two simple sentences, you might have to wait for a response from the visitor after the first question before you ask your second question. However, if you use a compund sentence, such as in all three inquiries, you will expect one response at the end of the compound sentence addressing both inquiries, that is, who the visitor would like to see, and also, the company he/she comes from.
So, you may inquire as follows:
May I know who you would like to see and whch company you are from?
or
Who would you like to see sir/ma'm, and which company should I say you are from?
or
Please tell me who you would like to see and also which company you work for.

'Hello, who would you like to consult with?' means;

• The person is asking who you would like to see at the company and for what reason you want to see them.

'With whom would you like to speak?' means;

• The front desk person is asking who is the person that you are coming to meet with or speak to.

'Which company are you representing?'

• This means that the person is asking you which company you are coming from and working for.