I have collected them in the collection as Tags, from a checkbox group. (sounds familiar?)
These are the " selectionTags1"

Maybe there is some conflict with something?
import wixData from 'wix-data';
import wixLocation from 'wix-location';
var refFields = []
//--------- USER-INTERFACE ---------------------
var DATASET = "#dataset1"
var DATABASE = "DatosPerfil"
//-------------------------------
var REFERENCE1 = "actividad"
var REFERENCE2 = "provincia"
var REFERENCE3 = "colaborador"
//--------- USER-INTERFACE ---------------------
$w.onReady(async function () {
refFields=[REFERENCE1, REFERENCE2, REFERENCE3]
//Options for CheckBox-1--------------------------------------------------------------
$w('#CB1').options = [
{"label": "Embajadores", "value": "Embajador"},
{"label": "Embajadas", "value": "Embajada"},
];
//Create-Unique-Dropdown--------------------------------------------------------------
wixData.query(DATABASE)
.limit(1000)
.find()
.then(results => {
const uniqueTitles1 = getUniqueTitles1(results.items);
const uniqueTitles2 = getUniqueTitles2(results.items);
$w("#DD1").options = buildOptions1(uniqueTitles1); //---> ACTIVIDAD
$w("#DD2").options = buildOptions2(uniqueTitles2); //---> PROVINCIA
});
//Dropdown_Buttons--------------------------------------------------------------------
$w('#DD1, #DD2').onChange(()=>{SEARCH_ENGINE();});
//Checkbox_Buttons--------------------------------------------------------------------
$w('#CB1').onChange(()=>{SEARCH_ENGINE();});
//Search_Buttons----------------------------------------------------------------------
$w('#BuscarBtn').onClick(()=>{ SEARCH_ENGINE(); });
//Reset_Buttons-----------------------------------------------------------------------
$w('#btnReset1').onClick(()=>{$w("#DD1").selectedIndex=undefined, SEARCH_ENGINE();});
$w('#btnReset2').onClick(()=>{$w("#DD2").selectedIndex=undefined, SEARCH_ENGINE();});
})
//------------- Functions ------------------------------------------------------------
function getUniqueTitles1(items) {const titlesOnly = items.map(item => item[refFields[0]]); return [...new Set(titlesOnly)];}
function buildOptions1(uniqueList1) {return uniqueList1.map(curr => {return {label:curr, value:curr};});}
//-------------
function getUniqueTitles2(items) {const titlesOnly = items.map(item => item[refFields[1]]); return [...new Set(titlesOnly)];}
function buildOptions2(uniqueList2) {return uniqueList2.map(curr => {return {label:curr, value:curr};});}
//-------------
function SEARCH_ENGINE() {console.log("Search-Engine started")
let filter = wixData.filter()
//DropDowns-------------------------------
let item1 = $w('#DD1').value //---> DropDown
let item2 = $w('#DD2').value //---> DropDown
//Checkbox-Group--------------------------
let item3 = $w('#CB1').value //---> CheckBox
//DropDowns-------------------------------
if (item1!==undefined && item1!=="") {filter = filter.eq(REFERENCE1, item1)}
if (item2!==undefined && item2!=="") {filter = filter.eq(REFERENCE2, item2)}
//Checkbox-Group--------------------------
if (item3!==undefined && item3!=="") {
for (var i = 0; i < item3.length; i++) {filter = filter.eq(REFERENCE3, item3[i])}
}
$w(DATASET).setFilter(filter)
.then(()=>{
result_COUNTER()
$w('#table1').refresh();
})
}
function RESET (parameter) {
$w("#DD1").selectedIndex = undefined;
$w("#DD2").selectedIndex = undefined;
$w('#CB1').value = undefined;
}
//Result-Counter----------------------------------------------
function result_COUNTER() {
let count = $w(DATASET).getTotalCount().toString();
console.log("COUNT = " + count)
$w('#resultCounter').text = count.toString()
}
///SearchBar
///EMAIL BTN
/**
* Adds an event handler that runs when the element is clicked.
* @param {$w.MouseEvent} event
*/
export function btnemail_click(event) {
wixLocation.to("mailto:") + $w('#dataset1').getCurrentItem().emailDeContacto.id
}
//HIDE ITEMS
$w.onReady(() => {
$w("#dataset1").onReady(() => {
// Gets the current item properties and stores them in a variable called item
const item = $w("#dataset1").getCurrentItem();
// Checks if the current item has a value in the "video" field
if (!item.fbEmpresa) {
$w("#FBimage").hide();
}
if (!item.instagramEmpresa) {
$w("#INSTempresa").hide();
}
if (!item.youtubeEmpresa) {
$w("#YTempresa").hide();
}
if (!item.twitter) {
$w("#TWempresa").hide();
}
if (!item.LINPersonal) {
$w("#LINKPersonal").hide();
}
if (!item.linEmpresa) {
$w("#LINEmpresa").hide();
}
if (!item.iniciativa) {
$w("#group1").collapse();
}
if (!item.URL) {
$w("#web").collapse();
}
});
});
export function repeater1_itemReady($item, itemData, index){
let options = [];
let tags = itemData.tipoActividad;
console.log("Item-Data: ", itemData)
console.log("Index: ", index)
console.log("Tags: ", tags)
for(var i =0; i < tags.length; i++){
options.push({"label": tags[i],"value": tags[i]})
if(i===tags.length){$item("#selectionTags1").options = options;}
}
}

