While Dashboards can handle a number of different HTML tags in something like the List widget, the <select> tag is not one of them. You might be able to accomplish something using <div> elements with some style tags. For instance, we have a dashboard where each list item has a series of buttons:
I don't know what other Dashboard functions you're using, but you might look into Experience Builder, as the List widget there is a lot more flexible in what it can do. Each list item could have a button that links to an anchored window. Inside the window could be a tabbed section widget with each of the relevant forms embedded and selectable by tab buttons.