How create additional filters?

The plugin uses the taxonomy terms of the selected post type to filter the map
So to add a new filter, you just need to create a new taxonomy for your post type.
This is a standard function of Wordperss, you can do it in several ways:

1 use snippets

2 via plugin Custom Post Type UI
to use the plugin for post type markers you need to change their visibility type to public

3 via online generator

you will have a new taxonomy

you can activate it in filters