By default, the platform does not have this option. You can use the following CSS code to make the LearnDash breadcrumb background transparent.
Please follow the steps below:
1. Go to BuddyBoss > Theme Options
2. Under Custom Codes, enable CSS
3. Append the following:
.learndash-wrapper .ld-lesson-status {
background: transparent !important;
}
4. Save changes