Take the subpage dropdown menu tasks down another level

Ask the community
1

I have a few pages that have 3 levels:
Main Topic 1
Sub Topic 1-1
Sub Topic 1-1a
Sub Topic 1-1b
Sub Topic 1-2
Sub Topic 1-2a
Sub Topic 1-2b
Sub Topic 1-2c
Main Topic 2

Would also like the option to keep the subpage dropdown tasks open/visable when the main topic is clicked.