Hey @DylanPhillips,
Firstly, welcome to the community - excited to have you!
As for sorting/filtering the board by the status or timeline of the subitems, whilst I am afraid it isn’t possible to filter directly by the subitems, what you can do is mirror the status/timeline column summary from the subitems into the parent item. From there, you can use quick or advanced filters to filter the board by the subitems status/timeline.
I understand this may not be the most ideal solution but I hope this can work for you in some way!
Let me know 
Bianca