DAZ doesn't have the same type thing. Essentially Textures, geometry, and morphs go in the /data folder. Anything else can go anywhere you want. And that goes pretty much for Poser Items used in DAZ also, you can move them around anywhere you want in the main poser divisions. IE, the pose mats can be put with the clothes or hair they belong with.

Traditionally you tend to stick those items in relevant sub-directories (people, props, envionment, etc) but the program can utilize them from anywhere. You'll also find some vendors that have the habit of separating their product along poser lines (sticking the camera presets under "cameras") for instance, rather than in a sub-directory off their product. I usually move those.

DAZ vendors will also sometimes use the traditional runtime/textures directory for UV textures particularly if they are supporting both DAZ and Poser. Since those are mapped as relative directories in DAZ also, it works fine.

Edit: Poser script files still have to be under /runtime for DAZ to load them, if you put them outside of /runtime they don't work, however there is a product offered here that can make shortcuts for them that you can put in the DAZ library. I find it to be very useful.