Acutally you may change to any companies as long as

the job position and job duty and the salary are the same after you filed I-485.

But the question to the immigration officer is why do you want to change? Is the current company be able to hire you after the long waiting list of the immigrant visa number many years later?

For your reference:
So as a result, if possible, stay the same company as long as you can.

Good luck!~

Yanzi