I am sure this can be a little hard to understand through words so I'll try my best. What I want is that when a button is pressed, instead of going to a whole new page, it just expands and shows some options, I tried uploading some pictures, but apparently, I need more reputation to do that.
Pictures on imgur (the first one is the menu, the second one is after one of the buttons are pressed:
Second: https://i.sstatic.net/05W0w.jpg
Do you mean you want an expandable listview?
if you mean this , I think this two open source project can help you .
https://github.com/guohai/and-expandable-listview
https://github.com/tjerkw/Android-SlideExpandableListView
if you mean you really want an activity when you click the button.
you can learn Fragment from official document.