After quite a bit of playing around, I've finally managed to get :-
1) INDI 1.8.8 working under the Astroberry environment
2) Takahashi ActiveFocuser INDI library (in INDI 18. working with Astroberry
To share at a high level what I did here :-
1) installed the necessary development packages for indi-core, and indi 3rd party. What is also further needed is apt install libhidapi-hidraw0 libhidapi-libusb0
2) the following udev rules file is also needed, otherwise the Takahashi ActiveFocuser hidraw0 has the wrong permissions :-
astroberry@astroberry:/etc/udev/rules.d $ cat 51-activefocuser.rules
# Takahashi ActiveFocuser
# indilib.org/focusers/activefocuser.html
#
# Put this file into /etc/udev/rules.d
#
# If you are creating a distribution package,
# put this into /usr/lib/udev/rules.d or /lib/udev/rules.d
# depending on your distribution
3) thereafter to download/compile indi-core (v1.8., and in my case needing the Vixen Starbook Ten INDI also needed indi 3rd-party downloaded/compiled (as well as ZWO ASI drivers)
Now the Takahashi ActiveFocuser (along with Vixen Starbook Ten, and ZWO ASI) under INDI 1.8.8 works in the Astroberry RaspbianOS environment.