Yes, it is the same with iOS and the tab bar should be visible everywhere.
Don't hide a tab bar when people navigate to different areas in your app. A tab bar enables global navigation for your app, so it should remain visible everywhere.
If I understand your questions correctly you would like to add more navigation menu items, on the bottom navigation bar in your app, than is possible (visual).
What we did in a concept was:
- Show 4 (most used) items in the bottom navigation bar
- The fifth item was a hamburger or submenu (the 3 dots) with the title 'More' on the most right side of the ...
With this design direction you are following a desktop homepage pattern of hotspots/cards and left nav that take you to the same place. This works as long as your cards can give you high level information that is relevant to the user. If you have no way of doing this, then hide the tab nav at the bottom until the user has made their first selection. Then ...