grafana/public/app/features/panel/partials/metrics_tab.html

<div class="query-editor-rows gf-form-group">
  <div ng-repeat="target in ctrl.panel.targets" ng-class="{'gf-form-disabled': target.hide}">
    <rebuild-on-change property="ctrl.panel.datasource || target.datasource" show-null="true">
      <plugin-component type="query-ctrl">
      </plugin-component>
    </rebuild-on-change>
	</div>

	<div class="gf-form-query">
		<div class="gf-form gf-form-query-letter-cell">
			<label class="gf-form-label">
				<span class="gf-form-query-letter-cell-carret">
					<i class="fa fa-caret-down"></i>
				</span>
				<span class="gf-form-query-letter-cell-letter">{{ctrl.panelCtrl.nextRefId}}</span>
			</label>
      <button class="btn btn-secondary gf-form-btn" ng-click="ctrl.addQuery()" ng-hide="ctrl.current.meta.mixed">
        Add Query
      </button>

      <div class="dropdown" ng-if="ctrl.current.meta.mixed">
        <gf-form-dropdown model="ctrl.addQueryDropdown"
                          get-options="ctrl.getOptions(false)"
                          on-change="ctrl.addMixedQuery($option)">
        </gf-form-dropdown>
      </div>
    </div>
  </div>
</div>

<!-- <query&#45;troubleshooter panel&#45;ctrl="ctrl.panelCtrl"></query&#45;troubleshooter> -->

<div class="gf-form-group">
  <div class="gf-form-inline">
    <div class="gf-form">
      <label class="gf-form-label">Panel Data Source</label>
      <gf-form-dropdown model="ctrl.panelDsValue"
                        lookup-text="true"
                        get-options="ctrl.getOptions(true)"
                        on-change="ctrl.datasourceChanged($option)">
      </gf-form-dropdown>
    </div>
  </div>
</div>

<rebuild-on-change property="ctrl.panel.datasource" show-null="true">
  <plugin-component type="query-options-ctrl">
  </plugin-component>
</rebuild-on-change>
</div>