Your devices will automatically apply updates from the Google Play Store or iOS App Stores. But if you wish to force an update, you can apply the Minimum Build Version for both iOS and Android. 

Navigate to BuddyBoss App - Configure. Here under General you will see the Minimum Build Version. You can set the iOS version.

Also the Android version. 

This is the way you can update the latest version of BuddyBoss App. 

Note: The build needs to be sent to Apple or Google and published to the App Store/Playstore first before selecting it as the minimum build version of your app.

Related Tutorial:

• How to set up General Configuration for BuddyBoss App