Here is a good discussion on creating buttons in Tableau: https://www.thedataschool.co.uk/niccolo-cirone/tableau-tip-week-wednesday-creating-dashboard-navigator-buttons/
It's definitely not like you would do in VB or another language though. You are essentially creating a worksheet that looks like a button, then using a filter action to switch to a new dashboard.
BTW. Keep an eye out for Tableau 2018.3, which should be out relatively soon. If the feature makes it to the final release, it will include buttons which will make this much easier: New features in beta: dashboard buttons, transparent backgrounds, and improved content browsing on Server and Online | …
Following up on this one. Let us know how we can help further.