How do I make tests repeatable in Cypress?

I have a site with various user types, (e.g. admin, client, etc.) while they all have functionality that is specific to their user type there is also some functionality that is shared. How do I define a set of tests so that they can be run when logged in as one user type, then run again when logged in as another user type?

I know about Cypress.Commands.add() but I haven't found a way to use it for a large set of repeatable tests, only for repeating the inner content of a single test.