There are several different possibilities to place the dashboards. The most suitable control may vary depending on the context.
Carousel tabs: Allow you to quickly switch between 2-3 options, other options are hidden. In general, tabs keep the options visible at all times which makes it quick and easy to switch between options. On the other hand the take up valuable space.
Tabs with "more" dropdown: Quickly switch between the 2 most common actions, all other options are hidden. If a user is not used to carousel tabs, then they might discover the hidden options more easily with the dropdown. Also differentiates between "common" dashboards (the ones on tabs) and not so important ones (in the dropdown). This might not be suitable if you want to convey them as equally important.
A single dropdown: All options are equally important, the dropdown possibly takes less space than a tab-bar but only the selected option is initially visible. All other options are invisible but again, discoverability shouldn't be that big of a deal, since dropdowns are commonly used. Switching options always requires 2 taps/clicks. If you decide to use a dropdown, make sure to read these guidelines from Nielsen Norman Group first.
A burger menu: Burger button in one of your top corners which opens a menu on click/tap. Might use less space than all above options but also hides the dashboard selection mechanism completely from your initial screen, which results in a worse discoverability (Hamburger menus).
For more information and inspiration, I recommend this article about Basic Patterns for Mobile Navigation.
To summarize: Be aware that different controls might be suitable for different situations. Think about your specific situation here before you look for an appropriate solution. Discoverability is only one factor of the equation; you could also consider visual weight/"importance" of those options, are there options more commonly used than others, number of clicks, screen real estate, internal consistency (consistency within your app), external consistency (consistency to other similar apps) etc.