At the moment, I can’t think of a way to do dodge and burn simultaneously in a single operation.
However, you could add two Color Overlay filters set to 50% grey, and set the blending modes to Linear Burn and Linear Dodge respectively. Then use the masking tool on each to darken and lighten as desired. This may seem like a more involved approach, but it might be more flexible since you could choose any level of grey (0-100%) independently for the dodging and burning, vary the opacity of the blending modes for each, and vary the opacity of the masking brush too.
Or, you could use a completely different approach such as separate Curves or Basic Adjustment filters for lightening and darkening with appropriate masking on each.
Scott, They should have you present a Studio 2 webinar called something like, “What To Do When You Can’t Do It (Easily) in Topaz Studio.” As a temp ‘Band-Aid’ till Topaz adds desired features functionality from its roadmap…