[JENKINS-75834] make sure only one instance of the dropdown is visible (#10786)

Author: krisstern

src/main/js/components/dropdowns/templates.js

@@ -36,6 +36,15 @@ function dropdown() {
     animation: "dropdown",
     duration: 250,
     onShow: (instance) => {
+      // Make sure only one instance is visible at all times
+      const dropdowns = document.querySelectorAll("[data-tippy-root]");
+      Array.from(dropdowns).forEach((element) => {
+        // Check if the Tippy.js instance exists
+        if (element && element._tippy) {
+          // To just hide the dropdown
+          element._tippy.hide();
+        }
+      });
       const referenceParent = instance.reference.parentNode;
 
       if (referenceParent.classList.contains("model-link")) {