U3818DW, KVM, PC, Raspberry Pi

I'm trying to configure my U3818DW with my desktop PC and a Raspberry Pi to use the KVM switch to move over 1) keyboard and 2) mouse. I would like to be able to do this while using the Raspberry Pi/PC in PBP mode AND when viewing them normally, one at a time. 

PC is connected with the USB B cable and DP.

Raspberry Pi is connected with another USB B cable and HDMI.

I've been trying for ages to configure this, and I know I'm missing something, even though I've been consulting the manual.

How should this be configured, and what options should I configure the two personalized buttons to use?

Thanks in advance. 

Just feedback for Dell: the manual for the U3818DW does not have anywhere NEAR enough information regarding the KVM switch; the phrase "KVM" is not mentioned once in its 57 pages. I would have greatly appreciated 1-2 pages on how to configure this.

See the online U3818DW User's Guide. kvm is mentioned ten times. Pages 30, 43, 53, 56
Dell-Admin