In Azure Devops Variable Groups you do something like:
FileRepo = 'FolderA' LogFile = '$(FileRepo)/Log.txt'
Is this possible in Azure App Configuration?
*UPDATE: When using the App Configration as an Azure Devops Task extenstion, $() references will work during pipelines.
No, this is not possible. Settings are flat and they do not support referencing to other settings values. You can try to do this programmatically, by replacing your tokens with real values, but there is nothing out of the box.