Ultimate member Groups search post

Hi
I have the search by groups in the page that displays ‘all groups’ or ‘my groups’, but I would like to be able to search by post / subject when I am on the page of a group. Because if the question has already been asked, I can find the conversation that talks about it, you understand? How to do that? I don’t see the option in the admin. Can we search by post? Or can we add a tag when I make a post in order to be able to search by tag on a post for example?
Thank you for your help