The new PowerApps Designer has a completely different look and feel from the old solution window. One of the improved areas is entity navigation. While the old solution window did have a few View options to choose from (Customizable, Custom, All), I rarely used this for navigation and preferred to just scroll to the entity I needed. In the new PowerApps designer, however, I find the filters to be very helpful and use them frequently!
To access the PowerApps designer, select the grid icon in the upper left corner. You may need to select “all apps” to find it:
Expand Data, then select Entities (called Tables as of 2021):
Choose from the filters to change the entities displayed–the “default” filter does not contain all entities! Select “All”, instead:
You can also search for entities instantly: