Fixing the state of dropdown icon

Author: eduard13

app/code/Magento/Ui/view/base/web/templates/grid/filters/elements/ui-select-optgroup.html

@@ -19,7 +19,7 @@
                 css: {
                     _selected: $parent.root.isSelected(option.value),
                     _hover: $parent.root.isHovered(option, $element),
-                    _expended: $parent.root.getLevelVisibility($data),
+                    _expended: $parent.root.getLevelVisibility($data) || $data.visible,
                     _unclickable: $parent.root.isLabelDecoration($data),
                     _last: $parent.root.addLastElement($data),
                     '_with-checkbox': $parent.root.showCheckbox

app/code/Magento/Ui/view/base/web/templates/grid/filters/elements/ui-select.html

@@ -160,7 +160,7 @@
                         css: {
                             _selected: $parent.isSelectedValue(option),
                             _hover: $parent.isHovered(option, $element),
-                            _expended: $parent.getLevelVisibility($data),
+                            _expended: $parent.getLevelVisibility($data) && $parent.showLevels($data),
                             _unclickable: $parent.isLabelDecoration($data),
                             _last: $parent.addLastElement($data),
                             '_with-checkbox': $parent.showCheckbox
@@ -174,6 +174,7 @@
                     <div class="admin__action-multiselect-dropdown"
                          data-bind="
                             click: function(event){
+                                $parent.showLevels($data);
                                 $parent.openChildLevel($data, $element, event);
                             },
                             clickBubble: false

app/design/adminhtml/Magento/backend/web/css/source/actions/_actions-multiselect.less

@@ -338,7 +338,7 @@
             border-top: @action-multiselect-tree-lines;
             height: 1px;
             top: @action-multiselect-menu-item__padding + @action-multiselect-tree-arrow__size/2;
-            width: @action-multiselect-tree-menu-item__margin-left + @action-multiselect-menu-item__padding;
+            width: @action-multiselect-tree-menu-item__margin-left;
         }
 
         //  Vertical dotted line