Leaflet地图实现仅显示激活底图层对应图例的问题求助

我正在制作一张包含7个底图层的Leaflet地图，由于图例数量太多，没办法全部在屏幕上展示，所以我需要实现一个功能：只有当前激活的底图层对应的图例才会显示出来。

目前我用htmlwidgets已经成功把所有图例都隐藏了，但遇到了一个问题——没法让当前激活的那个底图层的图例显示出来。

下面是我的图层控制代码：

addLayersControl(                                                #layer control 
    baseGroups = c("Parishes, plain",
                   "Unemployment rate", "Labor force participation rate", 
                   "FITAP, Parish","SNAP, Parish", "KCSP, Parish", 
                   "SNAP, zip"),
    overlayGroups = c("Community colleges", 
                      "Department of Corrections facilities", 
                      "Veterans Affairs Facilites"
    ),
    options = layersControlOptions(collapsed = FALSE)
  ) %>%
  showGroup("Parishes, plain")

我试过用hidegroup来控制图例组，但没有效果。再强调一下现状：通过htmlwidgets我已经把所有图例都隐藏了，但就是没法让激活图层的图例重新显示出来。

编辑补充：下面是我添加覆盖层及其对应图例的代码格式示例：

addCircleMarkers(                                                             #DOH
    data = ldh_geo,
    color = col_var,
    stroke = TRUE, 
    weight = 0.5,
    opacity = 1,
    fillColor = misc_pal$vintageviolet,
    popup = ~paste(
      "<b>Area:</b>", `LWDA  AREA (Office is located)`, "<br>"
    ),
    radius = dot_size,
    fillOpacity = 0.8,
    group = "Department of Health Facilities",
    options = pathOptions(pane = "markerPane")
  ) %>% 
  addLegend(
      position = "topleft",
      colors = misc_pal$vintageviolet, 
      labels = "DOH",  # Add corresponding labels
      title = "DOH Offices",
      layerId = "overlaydoh",
      opacity = 0.8
  ) 

备注：内容来源于stack exchange，提问作者LouisianaCodingNPC