how to harvest groups in telegram

I want to write a script that harvest telegram groups, as much as possible. the internal search functionality seems to be very limited; it shows few results for keyword.
I'm especially interested in new recently created groups.
does anyone know the method or have an idea how to obtain the groups addresses?

In this recent thread I made an answer about searching for telegram groups: https://www.blackhatworld.com/seo/how-to-search-for-more-telegram-groups.1601271/post-17723667
check it out