I am currently using a smooth bottom bar library.
you want to add badge count in BottomNavigationView
menu?
then use MaterialComponents
library
implementation 'com.google.android.material:material:1.2.0-alpha03'
use materialcomponent theme style.xml
<style name="AppTheme" parent="Theme.MaterialComponents.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
</style>
in your layout file
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="@+id/bottom_nav"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:menu="@menu/bottom_nav_menu"/>
add badge count like
val bottonnavBar = findViewById<BottomNavigationView>(R.id.bottom_nav)
var badge = bottonnavBar.getOrCreateBadge(R.id.action_add) //R.id.action_add is menu id
badge.number = 2 // it will show count on icon
hope it helpss...