Ok, we have some ERRORs here. You are not doing exactly what a suggest you.
Try this one…
import wixData from"wix-data";
$w.onReady(function(){ }
export function dropdown1_change(event) {xxx()}
function xxx() {
wixData.query("therapies")
.contains('therapy', $w('#dropdown1').value)
.or(wixData.query("therapies")
.contains('therapyType2', $w('#dropdown1').value))
.or(wixData.query("therapies")
.contains('therapyType3', $w('#dropdown1').value))
.find()
.then( (results) => {
console.log(results)
$w('#repeater1').data = results.items;
});
}