How to write a sentence properly when three or four incidents occurred in the past?

[Ayon Khan]

For example:
I knew he had worked in the company for five years before he got a promotion.
(Someone worked for a company for five years. After that, he got a promotion. I knew about it. )


We knew he thought the patient had died before the doctor came.
(At first, the patient died. Then the doctor came. Someone thought about this incident. We knew someone thought about it.)


Are my sentences grammatically correct? How to maintain the sequence of tense? Which tense structure should I follow?

 

[jutfrank]

I knew that at the time he got promoted that he'd been working for the company for five years.

The second sentence doesn't make good sense. I don't think it's natural to put all those elements into a single sentence.

 

[emsr2d2]

How [STRIKE]to[/STRIKE] can/should I maintain the sequence of tense?

Please note my correction above. We don't start questions with "How to". Learn that now - it will save you (and us) a lot of corrections in the future.