Here is a simple technique for the Shape Map in Power BI that allows additional focus on relevant polygons as well as adds some enhanced appeal. In my recent “Fish Oakland County!” submission to the Power BI Data Stories Gallery, I used a map that highlighted certain lakes depending on the data. As you apply different slicer values, outlines for the lakes with no data disappear, but the lake polygons remain.
The usual Shape Map behavior filters out all of the other lakes and puts focus only on selections.
The technique to maintain geographic perspective and keep the other lakes onscreen while only highlighting selected lake(s) is simple. Use two maps.
In the following image, the map on the left with the black background filters all the other lakes out. The map to the right without a background is an overlay that sits on top of the other map in the final visualization. Through a combination of Format options, you can achieve what appears in the published report. In addition, you could use Interactions and attempt even more (I’m not changing Interaction behavior for this particular report though).
The “focus” effect on the final report comes by virtue of using both a different border color and one that is much thicker. It looks terrible when viewed on its own, but it calls attention to the polygon when the other map rests atop.
Here’s an image of the Format options for the background (black) map. In the Default Color section, note that Show is disabled and that the Border Width is as high as it can get.
Disabling Show is important for the background map because otherwise all of the polygons have the border regardless of what is selected. Yuck!
Once you have the background map configured, you can work on the overlay by copying and pasting the same map, then altering the Format options. Here are the options for the overlay map. Note how Show is now enabled and the border width is as small as possible.
After that, you can simply drag the transparent overlay on top of the background map. You can use Bring Forward on the overlay to change the z-index if needed.