By default members of a BuddyPress site are redirected to the home page after logging in. BuddyPress Login Redirect is a simple plugin that lets you change this. Currently you can select from three different locations to redirect:
Personal Profile / Personal Activity
Site Wide Activity
If you don’t want to show your homepage to logged in users then you’re better off using BP Profile as Homepage instead. The BuddyPress Login Redirect plugin is more suitable if you want to redirect to one of the three options above. Download it for free from the WordPress plugin repository.