There are a few different ways this could be accomplished. The basics involve assigning a dash style to the tag for the cabinet outline. In this case I wanted to represent the toe kick but I didn’t want to show any of the internal stuff of the cabinet so I created an additional 2D object; a rectangle with a line drawn across it for the toe kick line. I put it on top of the cabinet but it could as easily be down on the floor or even above the counter top. It has been given its own tag as you can see below.
I set up a single plan view scene in SketchUp.
Then in LO, I positioned the viewport for the plan view and set the scale. This viewport shows the countertop only and is rendered as Vector. The viewport is on the Default layer here because I just used a simple paper template but in practice I would have layers specifically for viewports. I created an additional layer (Layer 3), made sure that layer was active, copied the Plan viewport, right clicked in empty space on the page, and chose Paste to current layer which put the copy of the viewport on Layer 3. For this viewport I turned off the visibility of the Cabinet, Counter top, and Pulls leaving only the Cabinet Outline visible. For that tag I changed the Dashes from Default to the dashed style, adjusted the weight and scale to make the dashes thinner that the outline for the counter top and done. The dashes are vector line work, they could easily be dimensioned. You could choose to show that layer or not in your PDF export.
Here I’ve moved that viewport off to the side.
Another option would be to skip the cabinet outline thing that I made and show only the cabinets with the dashes although you wouldn’t see the toe kick outline.
It would also be possible to do this with a single viewport using the Wireframe face style and giving the Cabinet tag the dashed style. This might add too much clutter in your drawing if your cabinets have internal details. Things like the edges of the inset door panels would show in wireframe, for example, but it depends upon how much detail you have put into modeling the casework.