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HTML 

              
                <!------ filter ------>
<div class="bg-light p-3 border-bottom mb-3">
  <div class="container-fluid">
    <div class="row">
      <div class="col-6">
        <select class="form-select js-filter" name="color">
          <option value="all">All Color</option>
          <option value="Red">Red</option>
          <option value="Blue">Blue</option>
          <option value="Green">Green</option>
        </select>
      </div>
      <div class="col-6">
        <select class="form-select js-filter" name="size">
          <option value="all">All Size</option>
          <option value="S">S</option>
          <option value="M">M</option>
          <option value="L">L</option>
        </select>
      </div>
    </div>
  </div>
</div>

<!------ result Message ------>
<p class="px-3"><span class="js-filter-msg"></span></p>

<!------ all items ------>
<div class="js-filter-items">
  <div class="js-filter-item bg-danger" data-color="Red" data-size="S">Red / S</div>
  <div class="js-filter-item bg-primary" data-color="Blue" data-size="M">Blue / M</div>
  <div class="js-filter-item bg-success" data-color="Green" data-size="M">Green / M</div>
  <div class="js-filter-item bg-danger" data-color="Red" data-size="L">Red / L</div>
  <div class="js-filter-item bg-primary" data-color="Blue" data-size="M">Blue / M</div>
  <div class="js-filter-item bg-success" data-color="Green" data-size="S">Green / S</div>
  <div class="js-filter-item bg-danger" data-color="Red" data-size="S">Red / S</div>
  <div class="js-filter-item bg-primary" data-color="Blue" data-size="L">Blue / L</div>
  <div class="js-filter-item bg-success" data-color="Green" data-size="S">Green / S</div>
  <div class="js-filter-item bg-danger" data-color="Red" data-size="L">Red / L</div>
  <div class="js-filter-item bg-primary" data-color="Blue" data-size="M">Blue / M</div>
  <div class="js-filter-item bg-success" data-color="Green" data-size="L">Green / L</div>
  <div class="js-filter-item bg-danger" data-color="Red" data-size="L">Red / L</div>
  <div class="js-filter-item bg-primary" data-color="Blue" data-size="S">Blue / S</div>
  <div class="js-filter-item bg-success" data-color="Green" data-size="L">Green / L</div>
  <div class="js-filter-item bg-danger" data-color="Red" data-size="M">Red / M</div>
  <div class="js-filter-item bg-danger" data-color="Red" data-size="M">Red / M</div>
  <div class="js-filter-item bg-success" data-color="Green" data-size="S">Green / S</div>
</div>
!

CSS 

              
                /***** for hidden *****/
.d-none {
  display: none;
}

/***** for layout（optional） *****/
.js-filter-items {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(2, 1fr);
  margin: 1rem;
}

.js-filter-item {
  padding: 1rem;
  text-align: center;
  color: #fff;
}
!

JS 

              
                function multi_filter(h, t, s, r = "") {
  let hidden = h;
  let targets = document.querySelectorAll(t);
  let selects = document.querySelectorAll(s);
  let result = document.querySelector(r);
  let result_msg = "";

  if (selects) {
    //****** for all select ******
    for (let i of selects) {
      i.addEventListener("change", () => {
        let hidden_num = 0;
        //*** for each target ***
        for (let ii of targets) {
          //*** delete hidden class ***
          ii.classList.remove(hidden);
          //*** check target every select ***
          for (let iii of selects) {
            //*** get select name value / option value / target data attribute ***
            let value = iii.value;
            let name = iii.getAttribute("name");
            let item_data = ii.getAttribute("data-" + name);
            //*** set hidden class ***
            // exist value & except all & item_data not match & no hidden class
            if (value && value !== "all" && value !== item_data && !ii.classList.contains(hidden)) {
              ii.classList.add(hidden);
              hidden_num++;
            }
          }
        }

        //****** result message ******
        if (result) {
          //*** not found ***
          if (hidden_num === targets.length) {
            result_msg = "No such thing..";
          }
          //*** found ***
          else {
            let result_num = targets.length - hidden_num;
            result_msg = result_num + " results";
          }
          result.innerText = result_msg;
        }
      });
    }
  }
}

//*** call ***
multi_filter("d-none", ".js-filter-item", ".js-filter", ".js-filter-msg");
!
999px

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