bp_are_previous_group_creation_steps_complete( string $step_slug )

function bp_are_previous_group_creation_steps_complete( $step_slug ) {
	$bp = buddypress();

	// If this is the first group creation step, return true.
	$keys = array_keys( $bp->groups->group_creation_steps );
	if ( array_shift( $keys ) == $step_slug ) {
		return true;
	}

	reset( $bp->groups->group_creation_steps );

	$previous_steps = array();

	// Get previous steps.
	foreach ( (array) $bp->groups->group_creation_steps as $slug => $name ) {
		if ( $slug === $step_slug ) {
			break;
		}

		$previous_steps[] = $slug;
	}

	return bp_is_group_creation_step_complete( $previous_steps );
}