With respect, you've now been given two possible solutions, both of which would work.
But let me spell out my preferred method once again.
With the PS4 connected to the network
1. Go to 192.168.0.1 and log in. 2. Go to DHCP and wait for the page to fully populate. 3. Click the radio button next to the PS4 entry which will add it's MAC and IP address to the Add reserved rule boxes. 4. Click Add Rule 5. Click Apply Changes.
This will now ensure that only the PS4 is given that IP address.
Next we need to deal with a security consideration BEFORE placing the PS4 in the DMZ, the fact that it will respond to mDNS requests from the internet at large. So we need to make sure it can't do this.
6. Go to Security->Port Forwarding 7. Click Create a New Rule 8. For Local IP add the last part of the PS4's IP address. 9. For Local Start and End ports enter 65535 10 For External Start and End Ports enter 5353 11 For Protocol Enter UDP 12 Select Enabled 13 Click Apply Changes
Finally we can now put the PS4 in the DMZ - Note there is a bug on the port forwarding and DMZ pages which will report changes have not been saved even when they have. This will occur when you go to the next step. Just click ignore.
14 Go to Security->DMZ 15 Select Enabled 16 Enter the last part of the PS4's IP address into the box. 17 Click Apply Changes
Now hopefully those instructions should be clear enough for you.
Only use Helpful answer if your problems been solved.
Ok do I go into DHCP settings 1st and make an IP address reservation by using the Add reserve rule setting?
The Hub 3.0 already assigned an Ip address of 192.168.0.14 for the PS4. Can I just add that IP to the add reserve rule reservation? Does that make it into a Static IP address before putting it into DMZ?
To be honest you've already answered your own question.
As you've correctly said use DHCP reservation to reserve the PS4's current address
Then go to the DMZ page and set the DMZ to point to 192.168.0.14.
Finally there is a vulnerability in the PS4 which means it responds to Multicast DNS requests from outside the local network. So to stop this happening add a port forwarding rule in the Superhub to forward port 5353 UDP to an unused IP address.