Relative clause with whose/whom/where.
1. We use whose in relative clauses instead of his/her/its/their.

We saw some people. Their car had broken down.

We saw some people whose car had broken down.
We use whose mostly for people:

What’s the name of the man whose car you borrowed?

She met someone whose brother she went to school with.
Compare the two words: who and whose.

I met a man who knows you. (he knows you)

I met a man whose sister knows you. (his sister knows you)
2. Whom is used when it is the object of the verb in the relative clause.

The woman whom I wanted to see was away.
You may use whom with a preposition (to whom/from whom/with whom).
The people with whom I play golf are wonderful.
As for spoken English, we don’t use whom. We usually prefer who or that, or nothing.
The woman I wanted to see… or  The woman who/that I wanted to see.
3. Where is used in a relative clause when you talk about a place.

I recently went back to the town where I grew up.

I would like to live in a place where there is a warm climate.