Thank you for reaching out to us. Selection filter modes are just commands. Since there is no GUI involved with most of them, you can just 'record' your actions with the script log and then 'play' that back. Just to be clear, you can also invoke commands that entail GUI, e.g., the "Selector .." command, but you cannot automate that GUI (as GUIs are generally not exposed in the API).

"""A simple script that disables all selection filters, and then just enables the polygons filter.
"""
from typing import Optional
import c4d

doc: c4d.documents.BaseDocument # The active document
op: Optional[c4d.BaseObject] # The active object, None if unselected

def main() -> None:
    """Called by Cinema 4D when the script is executed.
    """
    c4d.CallCommand(69000, 902) # Set selection filter to None.
    c4d.CallCommand(69000, 904) # Enable Polygon filter.

if __name__ == '__main__':
    main()
    c4d.EventAdd()

Cheers,
Ferdinand