How do i find google play music files in thegoogle phone nexus 5x

[AC Question]

I have the Nexus 5x Google phone and I have been trying to find the Google music files after I have purchased them... The sad thing About my phone is that I can't put an external SD card in my phone... I have to use internal drive of my phone... How can I access the files so that I may be able to us them in an video maker app that I have on my phone?