hierarchicalMenu with shows an arrow even when there are no children

I am not sure why that when we use a hierarchicalMenu, the arrow is displayed even when some items have no children.

Here is a snippet of one of our objects…

               "disciplines":{  
                  "lvl0":[  
                     "Sciences/Maths",
                     "Mechanical/Manufacturing",
                     "Materials & Minerals",
                     "Electronic & Electrical",
                     "Civil/Building",
                     "Chemical/Process",
                     "Aerospace"
                  ],
                  "lvl1":[  
                     "Sciences/Maths > Chemistry",
                     "Sciences/Maths > Maths",
                     "Sciences/Maths > Physics",
                     "Sciences/Maths > Science",
                     "Mechanical/Manufacturing > Automotive",
                     "Mechanical/Manufacturing > Manufacturing",
                     "Mechanical/Manufacturing > Mechanical",
                     "Materials & Minerals > Materials/Minerals",
                     "Electronic & Electrical > Electrical",
                     "Electronic & Electrical > Electronic",
                     "Civil/Building > Building Services",
                     "Civil/Building > Civil",
                     "Civil/Building > Quantity Surveying",
                     "Civil/Building > Structural",
                     "Chemical/Process > Chemical",
                     "Chemical/Process > Process",
                     "Aerospace > Aerospace"
                  ]
               },

As we don’t have a lvl2 defined at all, i’m not sure why any of the lvl1 items are showing the arrow (see screenshot below)

and this is how the hierarchicalMenu widget is setup…

			search.addWidget(
				instantsearch.widgets.hierarchicalMenu({
					container: '#discipline-facet',
					limit: 50,
					attributes: [
						'disciplines.lvl0',
						'disciplines.lvl1'
					],
					showParentLevel: true,
					sortBy: ['name:asc']
				})
			);

This arrow comes from the InstantSearch Algolia theme. It’s appended to all elements matching the CSS selector: .ais-hierarchical-menu--link::after. You can override it in CSS.