Unlisted dashboards will not be visible to any users other than the owner, but users with the dashboard link can access them directly with permission.
This section provides instructions on how to unlist a dashboard from the listing.
Click on the Share Permissions option in the Dashboards grid context menu.

Then, click on the Change option.

Select the checkbox Unlist dashboard from listingto mark the private/public dashboard as unlisted.

After selecting the checkbox, click Change to update the changes.

Uncheck the checkbox Unlist dashboard from listing to remove the dashboard from the unlisted list (to list the dashboard in the dashboard listing). Then, click Change to update the changes.

NOTE: Only the user who created the dashboard and the Administrator can unlist the dashboard.