When you are talking about two events or activities happening at the same time, in the present or in the past, you can use the word while.
I met her in 2017.
I was working in Colombia in 2017.
I met her in 2017 while I was working in Colombia.
I cooked dinner while my friend cleaned up.
I was watching TV while my sister was doing her homework.
Create three examples using different tenses: one example mixing simple past and past continuous, another example using two completed actions, using the past simple form and another example using the past continuous form.