When you want to give permissions , you go to Site Settings >> People and Groups.. And you will see the groups. But there is no search section. When we want to search a group , we are getting group by name. But how can we add a search panel to find what we search in website?
There is no such functionality in sharepoint to search something in peoples and groups, you have a option to search a user or group to check whether they exist in sharepoint and what permission they has. by using site setting -> under Users and permissions -> Site Permissions -> on ribbon you can see check permissions.
If you want, you can perform this action using powershell.