Pull info from a Related field within Matrix > within Super Table
I didn't test it yet but it should like this :

{% set entries = craft.entries().section('schedules').all() %}
{% for entry in entries %}
{% for block in entry.stageSchedule : %}
    {% if block.type == 'yourblocktype' : %}
         {% for item in block.schedule %}
            {{ item.timeOn }}
         {% endfor %}
    {% endif %}
{% endfor %}
{% endfor %}


I assume there is only one entry in schedules sections.
Please be remind block type is different with block name. 
Hope this help.