I am unsure of how convolutional neural networks treat several filters. Many of the examples I have seen only have filter at a time, and that is intuitive for me. Look at the nice visual tutorial here: https://www.jeremyjordan.me/convolutional-neural-networks/. If I look at the following visualization, I am okay with how they get from the input to the feature maps in the lower level concepts. However, I am unsure about how they get from the feature maps in the lower level concepts to the feature map in the higher level concept, and that largely stems from my confusion about how are multiple filters incorporated?