Connecting one of two Dropdown menu choices to list of things

Questions
1

Hey! Im a Bubble-newbie and I got a question:
I want to have two choices in a dropdown menu for instance - if the first choice is picked, e.g. ‘all universities’, a map should show all universities I entered in a list. If the second choice is clicked, e.g. ‘private universities’, the same map should show just the private universities I entered in another list.
The question is: How can I create those lists and link them to different choices of one and the same dropdown menu?

Thanks for help!!

2

Test the value of the dropdown selected, then update the data source of the map using the data list for the relevant selection using workflows.

3

Hey DaveA thanks for your quick help! I think I got an idea now, but could you tell me how to define the value of the dropdown selected?
That would be the last piece of my puzzle!