The new UI in Patch 7 allows to filter spells by their level, by clicking on the appropriate Spell Slot icon on the action bar. The level 1 spell slot is a bit wonky right now, asking us to choose a spell slot level even after we already selected it, but level 2 icon works as it should.

Now, can we have an additional button on the action bar which, when clicked, will display all cantrips the character knows?

Shadowheart, with her Guidance in particular, would benefit immensely from such a filter.