Codex is your friend. Check out the Slugs section among other tidbits in this page
https://codex.buddypress.org/how-to-guides/customizing-labels-messages-and-urls/
edit/ tooo slow 
This will tell you how to change url slugs
https://codex.buddypress.org/how-to-guides/changing-internal-configuration-settings/
Menu items/text can be changed by adjusting the link in header.php _e( ‘Groups’, ‘buddypress’ ) preferably via a copy of the file in a child theme.
Wow… that’s a lot of work (changing every mention of the word “group” in the po file one by one)! Even with that poedit program, it was a tedious and time consuming task because there was no “find and replace” functionality and with a text editor (I use TextPad), you have to be sure not to rename any file names. There needs to be s a simpler way. Maybe I don’t want to change it from “Groups” after all, LOL. But thanks for the links… I did learn a thing or two!
@jmarino
You did not scroll down to the end of the document to which @mercime linked. Look at the section entitled “Slugs”.
@jeffsayre I did see that and I considered only renaming the slugs but I was looking for more of a complete rename of the words “group” and “groups” site-wide. Poedit was helpful in that regard, but it would have taken me a while to manually edit each entry with those words in them. I may get around to doing that some day… just not today lol.
@jmarino
Based on your first post, I did not understand that as your goal. But you are correct in stating that if you want to change more than just the name of the slug, then you have no other choice but to create a custom language file.
@jeffsayre it wasn’t my goal when I started the topic, but as soon as I started to dig beneath the surface, it became clear that it would have to be all-or-nothing ordeal as renaming only the slugs might confuse some of my members.
I definitely do not recommend what humarahema suggested.
Follow what mercime says.
i followed the instructions but im confused as to what to upload and how to point the language files. i edited the newly created buddypress-en_Us.po file and created the folder languages in the wp-content folder. but it does’nt seem to be taking.
1) am i uploading the filed buddypress-en_US.po and .mo to that folder? and if so how do i tell buddy press to read from those launguage files the script i used from the example isnt working.
Wow… that’s a lot of work (changing every mention of the word “group” in the po file one by one)! Even with that poedit program, it was a tedious and time consuming task because there was no “find and replace” functionality and with a text editor (I use TextPad), you have to be sure not to rename any file names. There needs to be s a simpler way.
Wait till you realize that all your .po file changes will be lost the moment you update Buddypress.
