Ah, I see. In that case, I am going to fully guess that this is another limitations of the dashboards. I love dashboards as they're so simple to build and easy to share (plus, people expect them now). But their limitations sometimes stop me from using them. What I have done before to kind of cheat is to make a Web AppBuilder (or Experience Builder) app of the same map, configure it the way I want, and then add it as a tab underneath my main map in my dashboard. That way, users can do the added functionality that this app includes while remaining in the dashboard.
Here is a snippet of what that looks like for one of my dashboards: