The Dashboard Builder tool allows you to share your custom dashboards with either all the users in your account or with any specific users in your account.
From the My Dashboards page, click on the kebab menu on the dashboard card whose share settings you want to change.
Click on the ‘Open Share Settings’ option from the pop up menu.This will open the ‘Would You Like To Share This Board?’ page.
Choose your desired setting from the displayed options and click on ‘Save’.