Aaron Kyle Dennis

Any suggestions for how to make this work when allowing multiple selections?

The value: "" isn’t having any effect. With multiple: true, the value is an array, so you could set value: [] if you explicitly want to set the initial value to the empty array (which is already the default initial value).

Mike Bostock

Given you added multiple: true above, you likely want to change the options here accordingly: municipalities_list.filter(d => districts.includes(d["District"])).map(d => d["Municipality"]),

A bit of a follow up note to myself, but understanding this bit is critical: `d => districts.includes`