By default, the platform does not have this option. You can use the following CSS code to hide/remove Sign In and Sign Up buttons.

Please follow the steps below:

1. Go to BuddyBoss > Theme Options

2. Under Custom Codes, enable CSS

3. Append the following:

/*HIDE HEADER SIGN IN BUTTON*/
.bb-header-buttons .button.signin-button {
    display: none;
}

/*HIDE HEADER SIGN UP BUTTON*/
.bb-header-buttons .button.signup {
    display: none;
}

4. Save changes 

Note: Any modifications are considered as custom work already. Know more about our Support policy here: https://www.buddyboss.com/support-policy/