By default, the platform does not have this option. You can use the following CSS code.
Please follow the steps below:
1. Go to BuddyBoss > Theme Options
2. Under Custom Codes, enable CSS
3. Append the following:
#members-list.item-list .item-avatar img { border-radius: 0 !important; /* Set border-radius to 0 to make the image square */ }
CSS
4. Save changes.
Screenshots
Without code:
With Code: