unity – PropertyDrawer dependent on other property in monobehaviour

I would like to extend the unity editor for a scriptable object I am setting up.
I have a list of named maps defined on the SO, and afterwards I want to set up in another list some features that reference these maps.
Internally that is easily done by an integer index that references the proper map, but I would like to instead show a dropdown of the names that allow selecting the desired map.

How can I get the information about which options exist in the property drawer?