As salaamualaikum wa rahmatullilahi wabarkaatahu Sheikh:
I work in a different city than where my family is. My work is 250 kilometers
from my family (parents, and brothers). I work from Monday to Friday and
return to my family for Saturday and Sunday. I have an apartment where I
work. My question is can I shorten my salaat in my working city or are both
cities considered to be my home?
Jazakallahu khariran
wa salaamualaikum

Your home town, the one where your family
lives, is your home. The town which you intend to stay in for more than four
days is also considered a place of residence, according to the opinion of the
majority of scholars. Therefore you are not allowed to enjoy the concessions
of the traveler (i.e. shortening and combining the prayers) in either place.
However, you can shorten and combine prayers while traveling in between the
two places.

Refer to questions under Salaat
Ul-Musaafir (Prayer of the Traveler).