public function update_item( $request ) {
		$user         = bp_rest_get_user( $request['user_id'] );
		$group        = $this->groups_endpoint->get_group_object( $request['group_id'] );
		$action       = $request['action'];
		$role         = $request['role'];
		$group_id     = $group->id;
		$group_member = new BP_Groups_Member( $user->ID, $group_id );

		if ( 'promote' === $action ) {
			if ( ! $group_member->promote( $role ) ) {
				return new WP_Error(
					'bp_rest_group_member_failed_to_promote',
					__( 'Could not promote member.', 'buddypress' ),
					array(
						'status' => 500,
					)
				);
			}
		} elseif ( 'demote' === $action && 'member' !== $role ) {
			if ( ! $group_member->promote( $role ) ) {
				return new WP_Error(
					'bp_rest_group_member_failed_to_demote',
					__( 'Could not demote member.', 'buddypress' ),
					array(
						'status' => 500,
					)
				);
			}
		} elseif ( in_array( $action, [ 'demote', 'ban', 'unban' ], true ) ) {
			if ( ! $group_member->$action() ) {
				$messages = array(
					'demote' => __( 'Could not demote member from the group.', 'buddypress' ),
					'ban'    => __( 'Could not ban member from the group.', 'buddypress' ),
					'unban'  => __( 'Could not unban member from the group.', 'buddypress' ),
				);

				return new WP_Error(
					'bp_rest_group_member_failed_to_' . $action,
					$messages[ $action ],
					array(
						'status' => 500,
					)
				);
			}
		}

		// Setting context.
		$request->set_param( 'context', 'edit' );

		$retval = array(
			$this->prepare_response_for_collection(
				$this->prepare_item_for_response( $group_member, $request )
			),
		);

		$response = rest_ensure_response( $retval );

		/**
		 * Fires after a group member is updated via the REST API.
		 *
		 * @since 5.0.0
		 *
		 * @param WP_User          $user         The updated member.
		 * @param BP_Groups_Member $group_member The group member object.
		 * @param BP_Groups_Group  $group        The group object.
		 * @param WP_REST_Response $response     The response data.
		 * @param WP_REST_Request  $request      The request sent to the API.
		 */
		do_action( 'bp_rest_group_members_update_item', $user, $group_member, $group, $response, $request );

		return $response;
	}