Expanding timeline vertically to allow parallel intervals to be sh

[Mima]

How can I drop e.g. block intervals on block timeline parallerly? I.e. I have
several tasks (intervals) that occur during the same time period and I would
like to see them all at the same time.

Similarly, can timeline act as background on which milestones, intervals,
etc. could be dropped wherever vertically?

Regards,

Mima