Nexus 6 Why is there no individual volume settings for text notifications?

I want my ringer volume to be loud but I want to adjust my text alert notification to very soft, not silent and not vibrate; however, I cannot find any apps, or setting, that allow me to adjust the volumes separately, for text notifications and for ringer volume. Bc on that, this phone is not as awesome as I was led to believe. Even with my Samsung Galaxy S5 I could find a way to internally adjust everything separately: text, phone call ringer, alarms and earpiece volume.