Why does the meaning of the word とchange the initial phrase?

[Songz]

友達の田中さん typically means Lee's friend right?

Then why is the sentence
友達の田中さんと一緒にドイスへ行きます
I will go to Germany together with my friend Mr Lee

How did it change from Lee's friend to my friend Mr Lee?

 

[Toritoribe]

友達の田中さん typically means Lee's friend right?

Not really.
1)
田中さん is Mr or Ms Tanaka, not Mr Lee.
2)
友達の田中さん means My (or someone's) friend Tanaka. Tanaka's friend is 田中さんの友達. The order of the words is opposite.

友達の田中さんと一緒にドイスへ行きます
I will go to Germany together with my friend Mr Lee

There is a typo.
Germany is ドイツ, not ドイス.