The doctors whom you work with *in/at* the same hospital // ...*in/at* the same university...
1.
The doctors whom you work with *in/at* the same hospital were arrested for corruption.
→Is this sentence correct? Between "in" and "at", which preposition is better here? Or are the both correct?

2.
John, whom you studied with *in/at* the same university, was promoted to the manager of the company.
→Is this sentence correct? Between "in" and "at", which preposition is better here? Or are the both correct?

Thanks!

Question

The doctors whom you work with *in/at* the same hospital // ...*in/at* the same university...
1.
The doctors whom you work with *in/at* the same hospital were arrested for corruption.
→Is this sentence correct? Between "in" and "at", which preposition is better here? Or are the both correct?

2.
John, whom you studied with *in/at* the same university, was promoted to the manager of the company.
→Is this sentence correct? Between "in" and "at", which preposition is better here? Or are the both correct?

Thanks!

Answer

In the first case "in" or "at" is ok.

In the second sentence it would be more natural to say "studied at the same university".

Example of "at":
We ate dinner in room 203.  
not
We ate dinner at room 203.