No.
A purchase cannot be transferred from one platform to another and if you wish to play (for example) Cities: Skylines on your PC but you own it on your PS4, you need to buy it on PC.
Can I transfer my DLC/switch platform?
No.
A purchase cannot be transferred from one platform to another and if you wish to play (for example) Cities: Skylines on your PC but you own it on your PS4, you need to buy it on PC.