@JPMaine 

You can just plug the Ethernet cable from your computer into either of the Ethernet ports on your upstairs satellite Deco M5.  

By doing only that, that will not allow the computer to show on wifi.. Correct? Thanks again for your help.

Not sure what you are asking. Your SSID is your network name whether you are connected over Wi-Fi to a Deco Mesh satellite or via an ethernet cable. Even if you took an ethernet cable from your Primary Deco Node to a switch and then ran an ethernet cable 300' to your laptop, the laptop will still be connected to your Home Network which uses your Wi-Fi SSID name. Can you be more explicit what you are trying to either avoid or accomplish?

@DAServicesLLC 

First- I really appreciate your help. Thank you. I need to avoid the upstairs computer using WiFi to connect to the internet.  If I use my phone upstairs it should catch the wifi from other deco units downstairs. Thanks again.

@DAServicesLLC I ended up using 2 Deco M5's and connecting them with an Ethernet cable so it now shows as a wired connection and not wifi. Connecting just the Ethernet from 1 deco into computer didn't resolve issue although sure wish it had. Thanks again for your input.