Simply install the LunarG SDK (it's fast and easy), then make sure you've got the following environment variables set up in your bashrc file. For example:
export VULKAN_SDK='/path_to_home/VulkanSDK/1.3.216.0/x86_64'
export VK_LAYER_PATH="$VULKAN_SDK/etc/explicit_layer.d"
export PATH="$VULKAN_SDK/bin:$PATH"
As long as you're running a debug build of Filament, you should now see extra debugging spew in your console if there are any errors or performance issues being caught by validation.