At the moment, nesting within Infinity is managed with folders. This quite powerful and with the overview folder allows for a fair amount of manipulation.
What would be very helpful in the overview folder would be two things:
A table view that shows the nesting by folder (see attached)
A Gannt chart view with tasks on the left, nested by folder, and timelines on the right. (I made a separate feature request for this).
See attached example from Teamwork.com. On can see the nesting with the down arrows and indents down to task level (no down arrows - so only 2 items shown to task level).