If you’re using BP 1.5, it’s done the same way as you would do in regular WP installation.
http://codex.wordpress.org/Creating_a_Static_Front_Page
- Create a blank new Page titled e.g. Blog, News, etc. and publish it
- Go to admin dashboard Settings > Reading >Front Page Displays > A static page. Select “Activity” for Front page and then select “Blog” or whatever you named the new Page, for your Posts page.
Thanks to you. But another problem-(I am sorry i didn’t made myself clear first) I want show blogs and also activities at a time in the home page so that user can see both blogs and other activities all in one place