--- a/client/src/components/layers/Layerselect.vue	Thu Dec 12 17:13:34 2019 +0100
+++ b/client/src/components/layers/Layerselect.vue	Fri Dec 13 12:39:08 2019 +0100
@@ -2,6 +2,15 @@
   <div
     class="d-flex flex-column flex-start px-2 border-bottom"
     style="border-bottom-style: dashed !important;"
+    v-tooltip="{
+      content: rightclickLabel,
+      delay: {
+        show: 1000,
+        hide: 100
+      },
+      placement: 'bottom',
+      autohide: true
+    }"
   >
     <div class="d-flex" @click.right.prevent="selectSingle">
       <input
@@ -60,13 +69,19 @@
       "openLayersMaps",
       "isolinesLegendImgDataURL",
       "differencesLegendImgDataURL",
-      "ongoingRefresh"
+      "ongoingRefresh",
+      "singleLayerVisible"
     ]),
     ...mapGetters("map", ["openLayersMap"]),
     ...mapState("bottlenecks", ["selectedSurvey"]),
     layer() {
       return this.openLayersMap().getLayer(this.layerId);
     },
+    rightclickLabel() {
+      if (this.singleLayerVisible)
+        return this.$gettext("Right click to select previous layers");
+      return this.$gettext("Right click to select single layer");
+    },
     label() {
       return this.$gettext(this.layer.get("label"));
     }