How can we redirect to the site wide activity page after logging in

You can use our BuddyPress Redirect plugin to do so.

Navigate to the WB Plugins  >> BP Redirect >> Redirect For User Role >> Login Redirect Settings and set the login redirect of the user roles.

OR

You can also use custom page mapping and add the activity URL there.

For this, navigate to Appearance > Customizer >  General >Sign-in Popup | Register Form Fields, and choose the Activity Page in the dropdown named Login Redirect or you can also paste a custom URL of the Sitewide Activity Page.