Collapsing timeline

Hi, I’m still fairly new here so catching up as quickly as possible. I’m wondering if anyone can shed some light on what it means to collapse a timeline? I heard it in one of the videos and would appreciate a little more clarification. For example in referencing to healing trauma/generational trauma?

And to piggy back that, when we heal trauma/generational trauma how does that affect our parents/siblings and even our own children? 

I appreciate any guidance or reference to where I might get more info.

Sending love ❤️